linux-toradex.git/drivers/gpu/drm/msm/msm_gpu_devfreq.c, branch v6.0-rc4 Linux kernel for Apalis and Colibri modules drm/msm/gpu: Drop qos request if devm_devfreq_add_device() fails 2022-08-15T17:19:18+00:00 Bjorn Andersson bjorn.andersson@linaro.org 2022-07-08T16:26:32+00:00 02b9f2636209beb843ca501d47f7fddc8792b2d7 In the event that devm_devfreq_add_device() fails the device's qos freq list is left referencing df->idle_freq and df->boost_freq. Attempting to initialize devfreq again after a probe deferral will then cause invalid memory accesses in dev_pm_qos_add_request(). Fix this by dropping the requests in the error path. Fixes: 7c0ffcd40b16 ("drm/msm/gpu: Respect PM QoS constraints") Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> Reviewed-by: Rob Clark <robdclark@gmail.com> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Patchwork: https://patchwork.freedesktop.org/patch/493001/ Link: https://lore.kernel.org/r/20220708162632.3529864-1-bjorn.andersson@linaro.org Signed-off-by: Rob Clark <robdclark@chromium.org> 
In the event that devm_devfreq_add_device() fails the device's qos freq
list is left referencing df->idle_freq and df->boost_freq. Attempting to
initialize devfreq again after a probe deferral will then cause invalid
memory accesses in dev_pm_qos_add_request().

Fix this by dropping the requests in the error path.

Fixes: 7c0ffcd40b16 ("drm/msm/gpu: Respect PM QoS constraints")
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/493001/
Link: https://lore.kernel.org/r/20220708162632.3529864-1-bjorn.andersson@linaro.org
Signed-off-by: Rob Clark <robdclark@chromium.org>
drm/msm: Avoid unclocked GMU register access in 6xx gpu_busy 2022-07-06T15:38:06+00:00 Douglas Anderson dianders@chromium.org 2022-06-10T19:47:31+00:00 6694482a70e9536efbf2ac233cbf0c302d6e2dae From testing on sc7180-trogdor devices, reading the GMU registers needs the GMU clocks to be enabled. Those clocks get turned on in a6xx_gmu_resume(). Confusingly enough, that function is called as a result of the runtime_pm of the GPU "struct device", not the GMU "struct device". Unfortunately the current a6xx_gpu_busy() grabs a reference to the GMU's "struct device". The fact that we were grabbing the wrong reference was easily seen to cause crashes that happen if we change the GPU's pm_runtime usage to not use autosuspend. It's also believed to cause some long tail GPU crashes even with autosuspend. We could look at changing it so that we do pm_runtime_get_if_in_use() on the GPU's "struct device", but then we run into a different problem. pm_runtime_get_if_in_use() will return 0 for the GPU's "struct device" the whole time when we're in the "autosuspend delay". That is, when we drop the last reference to the GPU but we're waiting a period before actually suspending then we'll think the GPU is off. One reason that's bad is that if the GPU didn't actually turn off then the cycle counter doesn't lose state and that throws off all of our calculations. Let's change the code to keep track of the suspend state of devfreq. msm_devfreq_suspend() is always called before we actually suspend the GPU and msm_devfreq_resume() after we resume it. This means we can use the suspended state to know if we're powered or not. NOTE: one might wonder when exactly our status function is called when devfreq is supposed to be disabled. The stack crawl I captured was: msm_devfreq_get_dev_status devfreq_simple_ondemand_func devfreq_update_target qos_notifier_call qos_max_notifier_call blocking_notifier_call_chain pm_qos_update_target freq_qos_apply apply_constraint __dev_pm_qos_update_request dev_pm_qos_update_request msm_devfreq_idle_work Fixes: eadf79286a4b ("drm/msm: Check for powered down HW in the devfreq callbacks") Signed-off-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Rob Clark <robdclark@gmail.com> Patchwork: https://patchwork.freedesktop.org/patch/489124/ Link: https://lore.kernel.org/r/20220610124639.v4.1.Ie846c5352bc307ee4248d7cab998ab3016b85d06@changeid Signed-off-by: Rob Clark <robdclark@chromium.org> 
From testing on sc7180-trogdor devices, reading the GMU registers
needs the GMU clocks to be enabled. Those clocks get turned on in
a6xx_gmu_resume(). Confusingly enough, that function is called as a
result of the runtime_pm of the GPU "struct device", not the GMU
"struct device". Unfortunately the current a6xx_gpu_busy() grabs a
reference to the GMU's "struct device".

The fact that we were grabbing the wrong reference was easily seen to
cause crashes that happen if we change the GPU's pm_runtime usage to
not use autosuspend. It's also believed to cause some long tail GPU
crashes even with autosuspend.

We could look at changing it so that we do pm_runtime_get_if_in_use()
on the GPU's "struct device", but then we run into a different
problem. pm_runtime_get_if_in_use() will return 0 for the GPU's
"struct device" the whole time when we're in the "autosuspend
delay". That is, when we drop the last reference to the GPU but we're
waiting a period before actually suspending then we'll think the GPU
is off. One reason that's bad is that if the GPU didn't actually turn
off then the cycle counter doesn't lose state and that throws off all
of our calculations.

Let's change the code to keep track of the suspend state of
devfreq. msm_devfreq_suspend() is always called before we actually
suspend the GPU and msm_devfreq_resume() after we resume it. This
means we can use the suspended state to know if we're powered or not.

NOTE: one might wonder when exactly our status function is called when
devfreq is supposed to be disabled. The stack crawl I captured was:
  msm_devfreq_get_dev_status
  devfreq_simple_ondemand_func
  devfreq_update_target
  qos_notifier_call
  qos_max_notifier_call
  blocking_notifier_call_chain
  pm_qos_update_target
  freq_qos_apply
  apply_constraint
  __dev_pm_qos_update_request
  dev_pm_qos_update_request
  msm_devfreq_idle_work

Fixes: eadf79286a4b ("drm/msm: Check for powered down HW in the devfreq callbacks")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Rob Clark <robdclark@gmail.com>
Patchwork: https://patchwork.freedesktop.org/patch/489124/
Link: https://lore.kernel.org/r/20220610124639.v4.1.Ie846c5352bc307ee4248d7cab998ab3016b85d06@changeid
Signed-off-by: Rob Clark <robdclark@chromium.org>
drm/msm: Use div64_ul instead of do_div 2022-07-05T03:01:11+00:00 Wan Jiabing wanjiabing@vivo.com 2022-04-26T13:21:26+00:00 4400c3a1d48f7f7863ca65d24f99ad295b37726c Fix following coccicheck warning: drivers/gpu/drm/msm/msm_gpu_devfreq.c:72:1-7: WARNING: do_div() does a 64-by-32 division, please consider using div64_ul instead. Use div64_ul instead of do_div to avoid a possible truncation. Signed-off-by: Wan Jiabing <wanjiabing@vivo.com> Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Patchwork: https://patchwork.freedesktop.org/patch/483499/ Link: https://lore.kernel.org/r/20220426132126.686447-1-wanjiabing@vivo.com Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> 
Fix following coccicheck warning:
drivers/gpu/drm/msm/msm_gpu_devfreq.c:72:1-7: WARNING: do_div() does a 64-by-32 division, please consider using div64_ul instead.

Use div64_ul instead of do_div to avoid a possible truncation.

Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Acked-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Patchwork: https://patchwork.freedesktop.org/patch/483499/
Link: https://lore.kernel.org/r/20220426132126.686447-1-wanjiabing@vivo.com
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
drm/msm: return the average load over the polling period 2022-04-21T22:05:23+00:00 Chia-I Wu olvaffe@gmail.com 2022-04-16T00:33:14+00:00 78f815c1cf8fc5f05dc5cec29eb1895cb53470e9 simple_ondemand interacts poorly with clamp_to_idle. It only looks at the load since the last get_dev_status call, while it should really look at the load over polling_ms. When clamp_to_idle true, it almost always picks the lowest frequency on active because the gpu is idle between msm_devfreq_idle/msm_devfreq_active. This logic could potentially be moved into devfreq core. Fixes: 7c0ffcd40b16 ("drm/msm/gpu: Respect PM QoS constraints") Signed-off-by: Chia-I Wu <olvaffe@gmail.com> Cc: Rob Clark <robdclark@chromium.org> Link: https://lore.kernel.org/r/20220416003314.59211-3-olvaffe@gmail.com Signed-off-by: Rob Clark <robdclark@chromium.org> 
simple_ondemand interacts poorly with clamp_to_idle.  It only looks at
the load since the last get_dev_status call, while it should really look
at the load over polling_ms.  When clamp_to_idle true, it almost always
picks the lowest frequency on active because the gpu is idle between
msm_devfreq_idle/msm_devfreq_active.

This logic could potentially be moved into devfreq core.

Fixes: 7c0ffcd40b16 ("drm/msm/gpu: Respect PM QoS constraints")
Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
Cc: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20220416003314.59211-3-olvaffe@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>
drm/msm: simplify gpu_busy callback 2022-04-21T22:05:23+00:00 Chia-I Wu olvaffe@gmail.com 2022-04-16T00:33:13+00:00 15c411980bacddf294452fd1cf7308b14f3f8c63 Move tracking and busy time calculation to msm_devfreq_get_dev_status. Signed-off-by: Chia-I Wu <olvaffe@gmail.com> Cc: Rob Clark <robdclark@chromium.org> Link: https://lore.kernel.org/r/20220416003314.59211-2-olvaffe@gmail.com Signed-off-by: Rob Clark <robdclark@chromium.org> 
Move tracking and busy time calculation to msm_devfreq_get_dev_status.

Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
Cc: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20220416003314.59211-2-olvaffe@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>
drm/msm: remove explicit devfreq status reset 2022-04-21T22:05:23+00:00 Chia-I Wu olvaffe@gmail.com 2022-04-16T00:33:12+00:00 69f06a5d854f28ee65e15c20e488f21a063c1968 It is redundant since commit 7c0ffcd40b16 ("drm/msm/gpu: Respect PM QoS constraints") because dev_pm_qos_update_request triggers get_dev_status. Signed-off-by: Chia-I Wu <olvaffe@gmail.com> Cc: Rob Clark <robdclark@chromium.org> Link: https://lore.kernel.org/r/20220416003314.59211-1-olvaffe@gmail.com Signed-off-by: Rob Clark <robdclark@chromium.org> 
It is redundant since commit 7c0ffcd40b16 ("drm/msm/gpu: Respect PM QoS
constraints") because dev_pm_qos_update_request triggers get_dev_status.

Signed-off-by: Chia-I Wu <olvaffe@gmail.com>
Cc: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20220416003314.59211-1-olvaffe@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>
drm/msm/gpu: Fix crash on devices without devfreq support (v2) 2022-03-08T21:55:23+00:00 Rob Clark robdclark@chromium.org 2022-03-08T18:48:44+00:00 05afd57f4d34602a652fdaf58e0a2756b3c20fd4 Avoid going down devfreq paths on devices where devfreq is not initialized. v2: Change has_devfreq() logic [Dmitry] Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Reported-by: Anders Roxell <anders.roxell@linaro.org> Signed-off-by: Rob Clark <robdclark@chromium.org> Fixes: 6aa89ae1fb04 ("drm/msm/gpu: Cancel idle/boost work on suspend") Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org> Link: https://lore.kernel.org/r/20220308184844.1121029-1-robdclark@gmail.com 
Avoid going down devfreq paths on devices where devfreq is not
initialized.

v2: Change has_devfreq() logic [Dmitry]

Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
Reported-by: Anders Roxell <anders.roxell@linaro.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Fixes: 6aa89ae1fb04 ("drm/msm/gpu: Cancel idle/boost work on suspend")
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Link: https://lore.kernel.org/r/20220308184844.1121029-1-robdclark@gmail.com
drm/msm/gpu: Cancel idle/boost work on suspend 2022-01-25T16:54:41+00:00 Rob Clark robdclark@chromium.org 2022-01-08T18:09:11+00:00 6aa89ae1fb049614b7e03e24485bbfb96754a02b With system suspend using pm_runtime_force_suspend() we can't rely on the pm_runtime_get_if_in_use() trick to deal with devfreq callbacks after (or racing with) suspend. So flush any pending idle or boost work in the suspend path. Signed-off-by: Rob Clark <robdclark@chromium.org> Link: https://lore.kernel.org/r/20220108180913.814448-3-robdclark@gmail.com Signed-off-by: Rob Clark <robdclark@chromium.org> 
With system suspend using pm_runtime_force_suspend() we can't rely on
the pm_runtime_get_if_in_use() trick to deal with devfreq callbacks
after (or racing with) suspend.  So flush any pending idle or boost
work in the suspend path.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20220108180913.814448-3-robdclark@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>
drm/msm/gpu: Respect PM QoS constraints 2021-11-28T18:01:40+00:00 Rob Clark robdclark@chromium.org 2021-11-20T20:01:03+00:00 7c0ffcd40b161f56a7cea585297d64aeaf4d44a9 Re-work the boost and idle clamping to use PM QoS requests instead, so they get aggreggated with other requests (such as cooling device). This does have the minor side-effect that devfreq sysfs min_freq/ max_freq files now reflect the boost and idle clamping, as they show (despite what they are documented to show) the aggregated min/max freq. Fixing that in devfreq does not look straightforward after considering that OPPs can be dynamically added/removed. However writes to the sysfs files still behave as expected. v2: Use 64b math to avoid potential 32b overflow Signed-off-by: Rob Clark <robdclark@chromium.org> Link: https://lore.kernel.org/r/20211120200103.1051459-3-robdclark@gmail.com Signed-off-by: Rob Clark <robdclark@chromium.org> 
Re-work the boost and idle clamping to use PM QoS requests instead, so
they get aggreggated with other requests (such as cooling device).

This does have the minor side-effect that devfreq sysfs min_freq/
max_freq files now reflect the boost and idle clamping, as they show
(despite what they are documented to show) the aggregated min/max freq.
Fixing that in devfreq does not look straightforward after considering
that OPPs can be dynamically added/removed.  However writes to the
sysfs files still behave as expected.

v2: Use 64b math to avoid potential 32b overflow

Signed-off-by: Rob Clark <robdclark@chromium.org>
Link: https://lore.kernel.org/r/20211120200103.1051459-3-robdclark@gmail.com
Signed-off-by: Rob Clark <robdclark@chromium.org>
drm/msm: Increase gpu boost interval 2021-11-28T18:00:20+00:00 Akhil P Oommen akhilpo@codeaurora.org 2021-11-18T10:20:29+00:00 2a1ac5ba9080d4e86e597fb287f6992a9511b90c Currently, we boost gpu freq after 25ms of inactivity. This regresses some of the 30 fps usecases where the workload on gpu (at 33ms internval) is very small which it can finish at the lowest OPP before the deadline. Lets increase this inactivity threshold to 50ms (same as the current devfreq interval) to fix this. Signed-off-by: Akhil P Oommen <akhilpo@codeaurora.org> Link: https://lore.kernel.org/r/20211118154903.1.I2ed37cd8ad45a5a94d9de53330f973a62bd1fb29@changeid Signed-off-by: Rob Clark <robdclark@chromium.org> 
Currently, we boost gpu freq after 25ms of inactivity. This regresses
some of the 30 fps usecases where the workload on gpu (at 33ms internval)
is very small which it can finish at the lowest OPP before the deadline.
Lets increase this inactivity threshold to 50ms (same as the current
devfreq interval) to fix this.

Signed-off-by: Akhil P Oommen <akhilpo@codeaurora.org>
Link: https://lore.kernel.org/r/20211118154903.1.I2ed37cd8ad45a5a94d9de53330f973a62bd1fb29@changeid
Signed-off-by: Rob Clark <robdclark@chromium.org>