[PATCH] drm/amd/display: do not allocate display_mode_lib unnecessarily

[Leo]

Sorry for the delay, change LGTM. 

Reviewed-by: Leo Li <sunpeng.li at amd.com>

, and applied.

Thanks!
Leo

On 2020-01-24 5:18 a.m., Dor Askayo wrote:
> On Fri, Jan 17, 2020 at 12:59 PM Dor Askayo <dor.askayo at gmail.com> wrote:
>>
>> On Sat, Jan 4, 2020 at 2:23 PM Dor Askayo <dor.askayo at gmail.com> wrote:
>>>
>>> This allocation isn't required and can fail when resuming from suspend.
>>>
>>> Bug: https://gitlab.freedesktop.org/drm/amd/issues/1009
>>> Signed-off-by: Dor Askayo <dor.askayo at gmail.com>>>> ---
>>>  drivers/gpu/drm/amd/display/dc/core/dc.c | 17 +++++++++--------
>>>  1 file changed, 9 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
>>> index dd4731ab935c..83ebb716166b 100644
>>> --- a/drivers/gpu/drm/amd/display/dc/core/dc.c
>>> +++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
>>> @@ -2179,12 +2179,7 @@ void dc_set_power_state(
>>>         enum dc_acpi_cm_power_state power_state)
>>>  {
>>>         struct kref refcount;
>>> -       struct display_mode_lib *dml = kzalloc(sizeof(struct display_mode_lib),
>>> -                                               GFP_KERNEL);
>>> -
>>> -       ASSERT(dml);
>>> -       if (!dml)
>>> -               return;
>>> +       struct display_mode_lib *dml;
>>>
>>>         switch (power_state) {
>>>         case DC_ACPI_CM_POWER_STATE_D0:
>>> @@ -2206,6 +2201,12 @@ void dc_set_power_state(
>>>                  * clean state, and dc hw programming optimizations will not
>>>                  * cause any trouble.
>>>                  */
>>> +               dml = kzalloc(sizeof(struct display_mode_lib),
>>> +                               GFP_KERNEL);
>>> +
>>> +               ASSERT(dml);
>>> +               if (!dml)
>>> +                       return;
>>>
>>>                 /* Preserve refcount */
>>>                 refcount = dc->current_state->refcount;
>>> @@ -2219,10 +2220,10 @@ void dc_set_power_state(
>>>                 dc->current_state->refcount = refcount;
>>>                 dc->current_state->bw_ctx.dml = *dml;
>>>
>>> +               kfree(dml);
>>> +
>>>                 break;
>>>         }
>>> -
>>> -       kfree(dml);
>>>  }
>>>
>>>  void dc_resume(struct dc *dc)
>>> --
>>> 2.24.1
>>>
>>
>> I've been running with this fix applied on top of Fedora's
>> 5.3.16-300.fc31.x86_64 kernel for the past two weeks, suspending
>> and resuming often. This the first time since I bought my RX 580 8GB
>> more than a year ago that I can suspend and resume reliably.
>>
>> I'd appreciate a quick review for the above, it really is a trivial change.
>>
>> Thanks,
>> Dor
> 
> Bumping this up again. I've been running with this change for the past
> 20 days without issues.
> 
> Thanks,
> Dor
> 
> On Fri, Jan 17, 2020 at 12:59 PM Dor Askayo <dor.askayo at gmail.com> wrote:
>>
>> On Sat, Jan 4, 2020 at 2:23 PM Dor Askayo <dor.askayo at gmail.com> wrote:
>>>
>>> This allocation isn't required and can fail when resuming from suspend.
>>>
>>> Bug: https://gitlab.freedesktop.org/drm/amd/issues/1009
>>> Signed-off-by: Dor Askayo <dor.askayo at gmail.com>
>>> ---
>>>  drivers/gpu/drm/amd/display/dc/core/dc.c | 17 +++++++++--------
>>>  1 file changed, 9 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
>>> index dd4731ab935c..83ebb716166b 100644
>>> --- a/drivers/gpu/drm/amd/display/dc/core/dc.c
>>> +++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
>>> @@ -2179,12 +2179,7 @@ void dc_set_power_state(
>>>         enum dc_acpi_cm_power_state power_state)
>>>  {
>>>         struct kref refcount;
>>> -       struct display_mode_lib *dml = kzalloc(sizeof(struct display_mode_lib),
>>> -                                               GFP_KERNEL);
>>> -
>>> -       ASSERT(dml);
>>> -       if (!dml)
>>> -               return;
>>> +       struct display_mode_lib *dml;
>>>
>>>         switch (power_state) {
>>>         case DC_ACPI_CM_POWER_STATE_D0:
>>> @@ -2206,6 +2201,12 @@ void dc_set_power_state(
>>>                  * clean state, and dc hw programming optimizations will not
>>>                  * cause any trouble.
>>>                  */
>>> +               dml = kzalloc(sizeof(struct display_mode_lib),
>>> +                               GFP_KERNEL);
>>> +
>>> +               ASSERT(dml);
>>> +               if (!dml)
>>> +                       return;
>>>
>>>                 /* Preserve refcount */
>>>                 refcount = dc->current_state->refcount;
>>> @@ -2219,10 +2220,10 @@ void dc_set_power_state(
>>>                 dc->current_state->refcount = refcount;
>>>                 dc->current_state->bw_ctx.dml = *dml;
>>>
>>> +               kfree(dml);
>>> +
>>>                 break;
>>>         }
>>> -
>>> -       kfree(dml);
>>>  }
>>>
>>>  void dc_resume(struct dc *dc)
>>> --
>>> 2.24.1
>>>
>>
>> I've been running with this fix applied on top of Fedora's
>> 5.3.16-300.fc31.x86_64 kernel for
>> the past two weeks, suspending and resuming often. This the first time
>> since I bought my
>> RX 580 8GB more than a year ago that I can suspend and resume reliably.
>>
>> I'd appreciate a quick review for the above, it really is a trivial change.
>>
>> Thanks,
>> Dor