[PATCH 15/20] drm/amd/display: Reduce stack size of commit_planes_to_stream

[Harry Wentland]

On 2017-10-16 06:51 PM, andrey wrote:
> 
> 
> On 2017-10-16 04:31 PM, Harry Wentland wrote:
>> This function likes to blow 1024 stack size when something is
>> added to the addr struct. For now just dynamically allocate.
>>
>> Signed-off-by: Harry Wentland <harry.wentland at amd.com>
>> Reviewed-by: Tony Cheng <Tony.Cheng at amd.com>
>> Acked-by: Harry Wentland <Harry.Wentland at amd.com>
>> ---
>>   drivers/gpu/drm/amd/display/dc/core/dc.c | 19 +++++++++++++------
>>   1 file changed, 13 insertions(+), 6 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/display/dc/core/dc.c b/drivers/gpu/drm/amd/display/dc/core/dc.c
>> index ff6bd384aece..7a0593d4ca62 100644
>> --- a/drivers/gpu/drm/amd/display/dc/core/dc.c
>> +++ b/drivers/gpu/drm/amd/display/dc/core/dc.c
>> @@ -926,9 +926,9 @@ bool dc_commit_planes_to_stream(
>>           struct dc_state *state)
>>   {
>>       struct dc_surface_update updates[MAX_SURFACES];
> 
> Why this one is left on the stack then ?

This one is just tracking a bunch of pointers to more flip_addr, plane_info,
and scaling_info structs, so it's quite small.

This whole function is quite ugly and eventually needs to go anyways, along with
that whole dc_surface_update struct.

Harry

> 
> Thanks,
> Andrey
> 
>> -    struct dc_flip_addrs flip_addr[MAX_SURFACES];
>> -    struct dc_plane_info plane_info[MAX_SURFACES];
>> -    struct dc_scaling_info scaling_info[MAX_SURFACES];
>> +    struct dc_flip_addrs *flip_addr;
>> +    struct dc_plane_info *plane_info;
>> +    struct dc_scaling_info *scaling_info;
>>       int i;
>>       struct dc_stream_update *stream_update =
>>               kzalloc(sizeof(struct dc_stream_update), GFP_KERNEL);
>> @@ -938,10 +938,14 @@ bool dc_commit_planes_to_stream(
>>           return false;
>>       }
>>   +    flip_addr = kcalloc(MAX_SURFACES, sizeof(struct dc_flip_addrs),
>> +                GFP_KERNEL);
>> +    plane_info = kcalloc(MAX_SURFACES, sizeof(struct dc_plane_info),
>> +                 GFP_KERNEL);
>> +    scaling_info = kcalloc(MAX_SURFACES, sizeof(struct dc_scaling_info),
>> +                   GFP_KERNEL);
>> +
>>       memset(updates, 0, sizeof(updates));
>> -    memset(flip_addr, 0, sizeof(flip_addr));
>> -    memset(plane_info, 0, sizeof(plane_info));
>> -    memset(scaling_info, 0, sizeof(scaling_info));
>>         stream_update->src = dc_stream->src;
>>       stream_update->dst = dc_stream->dst;
>> @@ -980,6 +984,9 @@ bool dc_commit_planes_to_stream(
>>               new_plane_count,
>>               dc_stream, stream_update, plane_states, state);
>>   +    kfree(flip_addr);
>> +    kfree(plane_info);
>> +    kfree(scaling_info);
>>       kfree(stream_update);
>>       return true;
>>   }
>