- Jan 08, 2019
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Lyude Paul authoredCurrently, nouveau uses the yolo method of setting up MST displays: it uses the old VCPI helpers (drm_dp_find_vcpi_slots()) for computing the display configuration. These helpers don't take care to make sure they take a reference to the mstb port that they're checking, and additionally don't actually check whether or not the topology still has enough bandwidth to provide the VCPI tokens required. So, drop usage of the old helpers and move entirely over to the atomic helpers. Changes since v6: * Cleanup atomic check logic and remove a bunch of unneeded checks - danvet Changes since v5: * Update nv50_msto_atomic_check() and nv50_mstc_atomic_check() to the new requirements for drm_dp_atomic_find_vcpi_slots() and drm_dp_atomic_release_vcpi_slots() Signed-off-by:
Lyude Paul <lyude@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@redhat.com>
Cc: Jerry Zuo <Jerry.Zuo@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Juston Li <juston.li@intel.com> -
Lyude Paul authored
It occurred to me that we never actually check this! So let's start doing that. Signed-off-by:
Lyude Paul <lyude@redhat.com>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: David Airlie <airlied@redhat.com> Cc: Jerry Zuo <Jerry.Zuo@amd.com> Cc: Harry Wentland <harry.wentland@amd.com> Cc: Juston Li <juston.li@intel.com>
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Lyude Paul authored
There has been a TODO waiting for quite a long time in drm_dp_mst_topology.c: /* We cannot rely on port->vcpi.num_slots to update * topology_state->avail_slots as the port may not exist if the parent * branch device was unplugged. This should be fixed by tracking * per-port slot allocation in drm_dp_mst_topology_state instead of * depending on the caller to tell us how many slots to release. */ That's not the only reason we should fix this: forcing the driver to track the VCPI allocations throughout a state's atomic check is error prone, because it means that extra care has to be taken with the order that drm_dp_atomic_find_vcpi_slots() and drm_dp_atomic_release_vcpi_slots() are called in in order to ensure idempotency. Currently the only driver actually using these helpers, i915, doesn't even do this correctly: multiple ->best_encoder() checks with i915's current implementation would not be idempotent and would over-allocate VCPI slots, something I learned trying to implement fallback retraining in MST. So: simplify this whole mess, and teach drm_dp_atomic_find_vcpi_slots() and drm_dp_atomic_release_vcpi_slots() to track the VCPI allocations for each port. This allows us to ensure idempotency without having to rely on the driver as much. Additionally: the driver doesn't need to do any kind of VCPI slot tracking anymore if it doesn't need it for it's own internal state. Additionally; this adds a new drm_dp_mst_atomic_check() helper which must be used by atomic drivers to perform validity checks for the new VCPI allocations incurred by a state. Also: update the documentation and make it more obvious that these /must/ be called by /all/ atomic drivers supporting MST. Changes since v9: * Add some missing changes that were requested by danvet that I forgot about after I redid all of the kref stuff: * Remove unnecessary state changes in intel_dp_mst_atomic_check * Cleanup atomic check logic for VCPI allocations - all we need to check in compute_config is whether or not this state disables a CRTC, then free VCPI based off that Changes since v8: * Fix compile errors, whoops! Changes since v7: - Don't check for mixed stale/valid VCPI allocations, just rely on connector registration to stop such erroneous modesets Changes since v6: - Keep a kref to all of the ports we have allocations on. This required a good bit of changing to when we call drm_dp_find_vcpi_slots(), mainly that we need to ensure that we only redo VCPI allocations on actual mode or CRTC changes, not crtc_state->active changes. Additionally, we no longer take the registration of the DRM connector for each port into account because so long as we have a kref to the port in the new or previous atomic state, the connector will stay registered. - Use the small changes to drm_dp_put_port() to add even more error checking to make misusage of the helpers more obvious. I added this after having to chase down various use-after-free conditions that started popping up from the new helpers so no one else has to troubleshoot that. - Move some accidental DRM_DEBUG_KMS() calls to DRM_DEBUG_ATOMIC() - Update documentation again, note that find/release() should both not be called on the same port in a single atomic check phase (but multiple calls to one or the other is OK) Changes since v4: - Don't skip the atomic checks for VCPI allocations if no new VCPI allocations happen in a state. This makes the next change I'm about to list here a lot easier to implement. - Don't ignore VCPI allocations on destroyed ports, instead ensure that when ports are destroyed and still have VCPI allocations in the topology state, the only state changes allowed are releasing said ports' VCPI. This prevents a state with a mix of VCPI allocations from destroyed ports, and allocations from valid ports. Changes since v3: - Don't release VCPI allocations in the topology state immediately in drm_dp_atomic_release_vcpi_slots(), instead mark them as 0 and skip over them in drm_dp_mst_duplicate_state(). This makes it so drm_dp_atomic_release_vcpi_slots() is still idempotent while also throwing warnings if the driver messes up it's book keeping and tries to release VCPI slots on a port that doesn't have any pre-existing VCPI allocation - danvet - Change mst_state/state in some debugging messages to "mst state" Changes since v2: - Use kmemdup() for duplicating MST state - danvet - Move port validation out of duplicate state callback - danvet - Handle looping through MST topology states in drm_dp_mst_atomic_check() so the driver doesn't have to do it - Fix documentation in drm_dp_atomic_find_vcpi_slots() - Move the atomic check for each individual topology state into it's own function, reduces indenting - Don't consider "stale" MST ports when calculating the bandwidth requirements. This is needed because originally we relied on the state duplication functions to prune any stale ports from the new state, which would prevent us from incorrectly considering their bandwidth requirements alongside legitimate new payloads. - Add function references in drm_dp_atomic_release_vcpi_slots() - danvet - Annotate atomic VCPI and atomic check functions with __must_check - danvet Changes since v1: - Don't use the now-removed ->atomic_check() for private objects hook, just give drivers a function to call themselves Signed-off-by:Lyude Paul <lyude@redhat.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: David Airlie <airlied@redhat.com>
Cc: Jerry Zuo <Jerry.Zuo@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Juston Li <juston.li@intel.com> -
Lyude Paul authored
Changes since v6: - Move EXPORT_SYMBOL() for drm_dp_mst_topology_state_funcs to this commit - Document __drm_dp_mst_state_iter_get() and note that it shouldn't be called directly Signed-off-by:
Lyude Paul <lyude@redhat.com>
Reviewed-by: -
Lyude Paul authored
Going through the currently programmed payloads isn't safe without holding mgr->payload_lock, so actually do that and warn if anyone tries calling nv50_msto_payload() in the future without grabbing the right locks. Signed-off-by:Lyude Paul <lyude@redhat.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@redhat.com>
Cc: Jerry Zuo <Jerry.Zuo@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Juston Li <juston.li@intel.com> -
Lyude Paul authored
Same as we did for i915, but for nouveau this time. Additionally, we grab a malloc reference to the port that lasts for the entire lifetime of nv50_mstc, which gives us the guarantee that mstc->port will always point to valid memory for as long as the mstc stays around. Signed-off-by:Lyude Paul <lyude@redhat.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@redhat.com>
Cc: Jerry Zuo <Jerry.Zuo@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Juston Li <juston.li@intel.com> -
Lyude Paul authored
Now that we finally have a sane way to keep port allocations around, use it to fix the potential unchecked ->port accesses that nouveau makes by making sure we keep the mst port allocated for as long as it's drm_connector is accessible. Additionally, now that we've guaranteed that mstc->port is allocated for as long as we keep mstc around we can remove the connector registration checks for codepaths which release payloads, allowing us to release payloads on active topologies properly. These registration checks were only required before in order to avoid situations where mstc->port could technically be pointing at freed memory. Signed-off-by:Lyude Paul <lyude@redhat.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@redhat.com>
Cc: Jerry Zuo <Jerry.Zuo@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Juston Li <juston.li@intel.com> -
Lyude Paul authored
There is no need to look at the port's VCPI allocation before calling drm_dp_mst_deallocate_vcpi(), as we already have msto->disabled to let us avoid cleaning up an msto more then once. The DP MST core will never call drm_dp_mst_deallocate_vcpi() on it's own, which is presumably what these checks are meant to protect against. More importantly though, we're about to stop clearing mstc->port in the next commit, which means if we could potentially hit a use-after-free error if we tried to check mstc->port->vcpi here. So to make life easier for anyone who bisects this code in the future, use msto->disabled instead to check whether or not we need to deallocate VCPI instead. Signed-off-by:Lyude Paul <lyude@redhat.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@redhat.com>
Cc: Jerry Zuo <Jerry.Zuo@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Juston Li <juston.li@intel.com> -
Lyude Paul authored
Trying to destroy the connector using mstc->connector.funcs->destroy() if connector initialization fails is wrong: there is no possible codepath in nv50_mstc_new where nv50_mstm_add_connector() would return <0 and mstc would be non-NULL. Signed-off-by:Lyude Paul <lyude@redhat.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@redhat.com>
Cc: Jerry Zuo <Jerry.Zuo@amd.com>
Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Juston Li <juston.li@intel.com> -
Lyude Paul authored
Just like i915 and nouveau, it's a good idea for us to hold a malloc reference to the port here so that we never pass a freed pointer to any of the DP MST helper functions. Also, we stop unsetting aconnector->port in dm_dp_destroy_mst_connector(). There's literally no point to that assignment that I can see anyway. Signed-off-by:
Lyude Paul <lyude@redhat.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: David Airlie <airlied@redhat.com> Cc: Jerry Zuo <Jerry.Zuo@amd.com> Cc: Juston Li <juston.li@intel.com>
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Lyude Paul authored
So that the ports stay around until we've destroyed the connectors, in order to ensure that we don't pass an invalid pointer to any MST helpers once we introduce the new MST VCPI helpers. Changes since v1: * Move drm_dp_mst_get_port_malloc() to where we assign intel_connector->port - danvet Signed-off-by:
Lyude Paul <lyude@redhat.com>
Reviewed-by: Daniel Vetter <daniel@ffwll.ch> Cc: David Airlie <airlied@redhat.com> Cc: Jerry Zuo <Jerry.Zuo@amd.com> Cc: Harry Wentland <harry.wentland@amd.com> Cc: Juston Li <juston.li@intel.com>
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Lyude Paul authored
Up until now, freeing payloads on remote MST hubs that just had ports removed has almost never worked because we've been relying on port validation in order to stop us from accessing ports that have already been freed from memory, but ports which need their payloads released due to being removed will never be a valid part of the topology after they've been removed. Since we've introduced malloc refs, we can replace all of the validation logic in payload helpers which are used for deallocation with some well-placed malloc krefs. This ensures that regardless of whether or not the ports are still valid and in the topology, any port which has an allocated payload will remain allocated in memory until it's payloads have been removed - finally allowing us to actually release said payloads correctly. Signed-off-by:
Lyude Paul <lyude@redhat.com>
Reviewed-by: -
Lyude Paul authored
This has never actually worked, and isn't needed anyway: the driver's always going to try to deallocate VCPI when it tears down the display that the VCPI belongs to. Signed-off-by:
Lyude Paul <lyude@redhat.com>
Reviewed-by: -
Lyude Paul authored
While this isn't a complete fix, this will improve the reliability of drm_dp_get_last_connected_port_and_mstb() pretty significantly during hotplug events, since there's a chance that the in-memory topology tree may not be fully updated when drm_dp_get_last_connected_port_and_mstb() is called and thus might end up causing our search to fail on an mstb whose topology refcount has reached 0, but has not yet been removed from it's parent. Ideally, we should further fix this problem by ensuring that we deal with the potential for racing with a hotplug event, which would look like this: * drm_dp_payload_send_msg() retrieves the last living relative of mstb with drm_dp_get_last_connected_port_and_mstb() * drm_dp_payload_send_msg() starts building payload message At the same time, mstb gets unplugged from the topology and is no longer the actual last living relative of the original mstb * drm_dp_payload_send_msg() tries sending the payload message, hub times out * Hub timed out, we give up and run away-resulting in the payload being leaked This could be fixed by restarting the drm_dp_get_last_connected_port_and_mstb() search whenever we get a timeout, sending the payload to the new mstb, then repeating until either the entire topology is removed from the system or drm_dp_get_last_connected_port_and_mstb() fails. But since the above race condition is not terribly likely, we'll address that in a later patch series once we've improved the recovery handling for VCPI allocations in the rest of the DP MST helpers. Signed-off-by:
Lyude Paul <lyude@redhat.com>
Reviewed-by: -
Lyude Paul authored
The current way of handling refcounting in the DP MST helpers is really confusing and probably just plain wrong because it's been hacked up many times over the years without anyone actually going over the code and seeing if things could be simplified. To the best of my understanding, the current scheme works like this: drm_dp_mst_port and drm_dp_mst_branch both have a single refcount. When this refcount hits 0 for either of the two, they're removed from the topology state, but not immediately freed. Both ports and branch devices will reinitialize their kref once it's hit 0 before actually destroying themselves. The intended purpose behind this is so that we can avoid problems like not being able to free a remote payload that might still be active, due to us having removed all of the port/branch device structures in memory, as per: commit 91a25e46 ("drm/dp/mst: deallocate payload on port destruction") Which may have worked, but then it caused use-after-free errors. Being new to MST at the time, I tried fixing it; commit 263efde3 ("drm/dp/mst: Get validated port ref in drm_dp_update_payload_part1()") But, that was broken: both drm_dp_mst_port and drm_dp_mst_branch structs are validated in almost every DP MST helper function. Simply put, this means we go through the topology and try to see if the given drm_dp_mst_branch or drm_dp_mst_port is still attached to something before trying to use it in order to avoid dereferencing freed memory (something that has happened a LOT in the past with this library). Because of this it doesn't actually matter whether or not we keep keep the ports and branches around in memory as that's not enough, because any function that validates the branches and ports passed to it will still reject them anyway since they're no longer in the topology structure. So, use-after-free errors were fixed but payload deallocation was completely broken. Two years later, AMD informed me about this issue and I attempted to come up with a temporary fix, pending a long-overdue cleanup of this library: commit c54c7374 ("drm/dp_mst: Skip validating ports during destruction, just ref") But then that introduced use-after-free errors, so I quickly reverted it: commit 9765635b ("Revert "drm/dp_mst: Skip validating ports during destruction, just ref"") And in the process, learned that there is just no simple fix for this: the design is just broken. Unfortunately, the usage of these helpers are quite broken as well. Some drivers like i915 have been smart enough to avoid accessing any kind of information from MST port structures, but others like nouveau have assumed, understandably so, that drm_dp_mst_port structures are normal and can just be accessed at any time without worrying about use-after-free errors. After a lot of discussion, me and Daniel Vetter came up with a better idea to replace all of this. To summarize, since this is documented far more indepth in the documentation this patch introduces, we make it so that drm_dp_mst_port and drm_dp_mst_branch structures have two different classes of refcounts: topology_kref, and malloc_kref. topology_kref corresponds to the lifetime of the given drm_dp_mst_port or drm_dp_mst_branch in it's given topology. Once it hits zero, any associated connectors are removed and the branch or port can no longer be validated. malloc_kref corresponds to the lifetime of the memory allocation for the actual structure, and will always be non-zero so long as the topology_kref is non-zero. This gives us a way to allow callers to hold onto port and branch device structures past their topology lifetime, and dramatically simplifies the lifetimes of both structures. This also finally fixes the port deallocation problem, properly. Additionally: since this now means that we can keep ports and branch devices allocated in memory for however long we need, we no longer need a significant amount of the port validation that we currently do. Additionally, there is one last scenario that this fixes, which couldn't have been fixed properly beforehand: - CPU1 unrefs port from topology (refcount 1->0) - CPU2 refs port in topology(refcount 0->1) Since we now can guarantee memory safety for ports and branches as-needed, we also can make our main reference counting functions fix this problem by using kref_get_unless_zero() internally so that topology refcounts can only ever reach 0 once. Changes since v3: * Remove rebase detritus - danvet * Split out purely style changes into separate patches - hwentlan Changes since v2: * Fix commit message - checkpatch * s/)-1/) - 1/g - checkpatch Changes since v1: * Remove forward declarations - danvet * Move "Branch device and port refcounting" section from documentation into kernel-doc comments - danvet * Export internal topology lifetime functions into their own section in the kernel-docs - danvet * s/@/&/g for struct references in kernel-docs - danvet * Drop the "when they are no longer being used" bits from the kernel docs - danvet * Modify diagrams to show how the DRM driver interacts with the topology and payloads - danvet * Make suggested documentation changes for drm_dp_mst_topology_get_mstb() and drm_dp_mst_topology_get_port() - danvet * Better explain the relationship between malloc refs and topology krefs in the documentation for drm_dp_mst_topology_get_port() and drm_dp_mst_topology_get_mstb() - danvet * Fix "See also" in drm_dp_mst_topology_get_mstb() - danvet * Rename drm_dp_mst_topology_get_(port|mstb)() -> drm_dp_mst_topology_try_get_(port|mstb)() and drm_dp_mst_topology_ref_(port|mstb)() -> drm_dp_mst_topology_get_(port|mstb)() - danvet * s/should/must in docs - danvet * WARN_ON(refcount == 0) in topology_get_(mstb|port) - danvet * Move kdocs for mstb/port structs inline - danvet * Split drm_dp_get_last_connected_port_and_mstb() changes into their own commit - danvet Signed-off-by:
Lyude Paul <lyude@redhat.com>
Reviewed-by: -
Lyude Paul authored
s/drm_dp_get_validated_port_ref/drm_dp_mst_topology_get_port_validated/ s/drm_dp_put_port/drm_dp_mst_topology_put_port/ s/drm_dp_get_validated_mstb_ref/drm_dp_mst_topology_get_mstb_validated/ s/drm_dp_put_mst_branch_device/drm_dp_mst_topology_put_mstb/ This is a much more consistent naming scheme, and will make even more sense once we redesign how the current refcounting scheme here works. Signed-off-by:
Lyude Paul <lyude@redhat.com>
Reviewed-by: -
Lyude Paul authored
Split some stuff across multiple lines Signed-off-by:
Lyude Paul <lyude@redhat.com>
Reviewed-by: -
Lyude Paul authored
Fix some indenting, split some stuff across multiple lines. Signed-off-by:
Lyude Paul <lyude@redhat.com>
Reviewed-by: -
Lyude Paul authored
Split some stuff across multiple lines, remove some unnecessary braces Signed-off-by:
Lyude Paul <lyude@redhat.com>
Reviewed-by: -
Lyude Paul authored
Reindent some stuff, and split some stuff across multiple lines so we aren't going over the text width limit. Signed-off-by:
Lyude Paul <lyude@redhat.com>
Reviewed-by: -
Noralf Trønnes authored
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Noralf Trønnes authored
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Noralf Trønnes authored
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Noralf Trønnes authored
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Noralf Trønnes authored
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Noralf Trønnes authored
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After drm_fb_helper_fbdev_setup calls drm_fb_helper_init, "dev->fb_helper" will be initialized (and thus drm_fb_helper_fini will have some effect). After that, drm_fb_helper_initial_config is called which may call the "fb_probe" driver callback. This driver callback may call drm_fb_helper_defio_init (as is done by drm_fb_helper_generic_probe) or set a framebuffer (as is done by bochs) as documented. These are normally cleaned up on exit by drm_fb_helper_fbdev_teardown which also calls drm_fb_helper_fini. If an error occurs after "fb_probe", but before setup is complete, then calling just drm_fb_helper_fini will leak resources. This was triggered by df2052cc ("bochs: convert to drm_fb_helper_fbdev_setup/teardown"): [ 50.008030] bochsdrmfb: enable CONFIG_FB_LITTLE_ENDIAN to support this framebuffer [ 50.009436] bochs-drm 0000:00:02.0: [drm:drm_fb_helper_fbdev_setup] *ERROR* fbdev: Failed to set configuration (ret=-38) [ 50.011456] [drm] Initialized bochs-drm 1.0.0 20130925 for 0000:00:02.0 on minor 2 [ 50.013604] WARNING: CPU: 1 PID: 1 at drivers/gpu/drm/drm_mode_config.c:477 drm_mode_config_cleanup+0x280/0x2a0 [ 50.016175] CPU: 1 PID: 1 Comm: swapper/0 Tainted: G T 4.20.0-rc7 #1 [ 50.017732] EIP: drm_mode_config_cleanup+0x280/0x2a0 ... [ 50.023155] Call Trace: [ 50.023155] ? bochs_kms_fini+0x1e/0x30 [ 50.023155] ? bochs_unload+0x18/0x40 This can be reproduced with QEMU and CONFIG_FB_LITTLE_ENDIAN=n. Link: https://lkml.kernel.org/r/20181221083226.GI23332@shao2-debian Link: https://lkml.kernel.org/r/20181223004315.GA11455@al Fixes: 87412163 ("drm/fb-helper: Add drm_fb_helper_fbdev_setup/teardown()") Reported-by:
kernel test robot <rong.a.chen@intel.com> Cc: Noralf Trønnes <noralf@tronnes.org> Signed-off-by:
Peter Wu <peter@lekensteyn.nl> Reviewed-by:
Noralf Trønnes <noralf@tronnes.org> Signed-off-by:
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Noralf Trønnes authored
If register_framebuffer() fails during fbdev setup we will leak the framebuffer, the GEM buffer and the shadow buffer for defio. This is because drm_fb_helper_fbdev_setup() just calls drm_fb_helper_fini() on error not taking into account that register_framebuffer() can fail. Since the generic emulation uses DRM client for its framebuffer and backing buffer in addition to a shadow buffer, it's necessary to open code drm_fb_helper_fbdev_setup() to properly handle the error path. Error cleanup is removed from .fb_probe and is handled by one function for all paths. Fixes: 9060d7f4 ("drm/fb-helper: Finish the generic fbdev emulation") Reported-by:
Gerd Hoffmann <kraxel@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190105181846.26495-1-noralf@tronnes.org
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On Fri, Dec 28, 2018 at 12:11:12AM +0100, Heiner Kallweit wrote: > > OK, did as you advised and here comes the trace. That's the related dmesg part: > > [ 1479.025092] x86: Booting SMP configuration: > [ 1479.025129] smpboot: Booting Node 0 Processor 1 APIC 0x2 > [ 1479.094715] NOHZ: local_softirq_pending 202 > [ 1479.096557] smpboot: CPU 1 is now offline > > Hope it helps. > Heiner > > > # tracer: nop > # > # _-----=> irqs-off > # / _----=> need-resched > # | / _---=> hardirq/softirq > # || / _--=> preempt-depth > # ||| / delay > # TASK-PID CPU# |||| TIMESTAMP FUNCTION > # | | | |||| | | [...] > <idle>-0 [001] d.h2 1479.111017: softirq_raise: vec=9 [action=RCU] > <idle>-0 [001] d.h2 1479.111026: softirq_raise: vec=7 [action=SCHED] > <idle>-0 [001] ..s2 1479.111035: softirq_entry: vec=1 [action=TIMER] > <idle>-0 [001] ..s2 1479.111040: softirq_exit: vec=1 [action=TIMER] > <idle>-0 [001] ..s2 1479.111040: softirq_entry: vec=7 [action=SCHED] > <idle>-0 [001] ..s2 1479.111052: softirq_exit: vec=7 [action=SCHED] > <idle>-0 [001] ..s2 1479.111052: softirq_entry: vec=9 [action=RCU] > <idle>-0 [001] .Ns2 1479.111079: softirq_exit: vec=9 [action=RCU] > cpuhp/1-13 [001] dNh2 1479.112930: softirq_raise: vec=1 [action=TIMER] > cpuhp/1-13 [001] dNh2 1479.112935: softirq_raise: vec=9 [action=RCU] Interesting, the softirq is raised from hardirq but it's not handled in the end of the IRQ. Are you running threaded IRQS by any chance? If so I would expect ksoftirqd to handle the pending work before we go idle. However I can imagine a small window where such an expectation may not be met: if the softirq is raised after the ksoftirqd thread is parked (CPUHP_AP_SMPBOOT_THREADS), which is right before we disable the CPU (CPUHP_TEARDOWN_CPU). I don't know if we can afford to ignore a softirq even at this late stage. We should probably avoid leaking any. So here is a possible fix, if you don't mind trying:
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Jani Nikula authored
Minimal change to nuke the static buf. Reviewed-by:
Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by:
Jani Nikula <jani.nikula@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190107145149.10069-1-jani.nikula@intel.com
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Gerd Hoffmann authored
Just call drm_fence_put directly instead. Also set vgfb->fence to NULL after dropping the reference. Signed-off-by:
Ezequiel Garcia <ezequiel@collabora.com> Link: http://patchwork.freedesktop.org/patch/msgid/20181219122708.4586-4-kraxel@redhat.com
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Gerd Hoffmann authored
Sending the flush command only makes sense if we actually have a framebuffer attached to the scanout (handle != 0). Signed-off-by:
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Gerd Hoffmann authored
If we got an error response code from the host, print it to the log. Signed-off-by:
Oleksandr Andrushchenko <oleksandr_andrushchenko@epam.com> Link: http://patchwork.freedesktop.org/patch/msgid/20181219122708.4586-2-kraxel@redhat.com
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As per the VirtIO spec, the virtqueues must be reset during cleanup (see "3.3.1 Driver Requirements: Device Cleanup"). Signed-off-by:
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The virtio_gpu_output is a member of struct virtio_gpu_device and is not a dynamically-allocated chunk, so it's wrong to kfree() it. Removing it fixes a memory corruption BUG() that can be triggered when the virtio-gpu driver is removed. Signed-off-by:
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Chris Wilson authored
Ignore trying to shrink from i915 if we fail to acquire the struct_mutex in the shrinker while performing direct-reclaim. The trade-off being (much) lower latency for non-i915 clients at an increased risk of being unable to obtain a page from direct-reclaim without hitting the oom-notifier. The proviso being that we still keep trying to hard obtain the lock for kswapd so that we can reap under heavy memory pressure. v2: Taint all mutexes taken within the shrinker with the struct_mutex subclass as an early warning system, and drop I915_SHRINK_ACTIVE from vmap to reduce the number of dangerous paths. We also have to drop I915_SHRINK_ACTIVE from oom-notifier to be able to make the same claim that ACTIVE is only used from outside context, which fits in with a longer strategy of avoiding stalls due to scanning active during shrinking. The danger in using the subclass struct_mutex is that we declare ourselves more knowledgable than lockdep and deprive ourselves of automatic coverage. Instead, we require ourselves to mark up any mutex taken inside the shrinker in order to detect lock-inversion, and if we miss any we are doomed to a deadlock at the worst possible moment. Signed-off-by:
Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190107115509.12523-1-chris@chris-wilson.co.uk
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Jani Nikula authored
Generally catch up with 5.0-rc1, and specifically get the changes: 96d4f267 ("Remove 'type' argument from access_ok() function") 0b2c8f8b ("i915: fix missing user_access_end() in page fault exception case") 594cc251 ("make 'user_access_begin()' do 'access_ok()'") Signed-off-by:
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Simona Vetter authored
The current one essentially means you need CMA or a vmalloc backed object, which makes fbdev emulation a special case. Since implementing this will be quite a bit of work, capture the idea in a TODO. Cc: Noralf Trønnes <noralf@tronnes.org> Acked-by:
Daniel Vetter <daniel.vetter@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190107102238.7789-1-daniel.vetter@ffwll.ch
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The "chip->dsp_spos_instance" can be NULL on some of the ealier error paths in snd_cs46xx_create(). Reported-by:
"Yavuz, Tuba" <tuba@ece.ufl.edu> Signed-off-by:
Dan Carpenter <dan.carpenter@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by:
Takashi Iwai <tiwai@suse.de>
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Jani Nikula authored
Merge tag 'topic/drmp-cleanup-2019-01-02' of git://anongit.freedesktop.org/drm/drm-intel into drm-intel-next-queued Make some drm headers self-contained with includes and forward declarations. This topic branch has already been merged to drm-misc-next as commit 1c95f662 ("Merge tag 'topic/drmp-cleanup-2019-01-02' of git://anongit.freedesktop.org/drm/drm-intel into drm-misc-next"). Now merge it to drm-intel-next-queued to unblock some further drmP.h cleanup without having to wait for a backmerge. Signed-off-by:
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