[Mesa-dev] [PATCH 2/2] i965: return the fourcc saved in __DRIimage

[Tapani Pälli]

On 05.04.2018 18:43, James Xiong wrote:
> On Thu, 5 Apr 2018 14:30:02 +0300
> Tapani Pälli <tapani.palli at intel.com> wrote:
> 
>> On 04/05/2018 02:51 AM, James Xiong wrote:
>>> From: "Xiong, James" <james.xiong at intel.com>
>>>
>>> The planar_format in __DRIimage contains the original fourcc
>>> used to create the image, if it's set, return the saved fourcc
>>> directly; Otherwise fall back to the old way.
>>>
>>> Also we should validate the input parameter "value" first as it
>>> might be NULL based on the SPEC.
>>>
>>> v2: fall back to intel_lookup_fourcc() when planar_format is NULL
>>>     (by Dongwon & Matt Roper)
>>>
>>> Signed-off-by: Xiong, James <james.xiong at intel.com>
>>> ---
>>>    src/mesa/drivers/dri/i965/intel_screen.c | 15 ++++++++++++---
>>>    1 file changed, 12 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/src/mesa/drivers/dri/i965/intel_screen.c
>>> b/src/mesa/drivers/dri/i965/intel_screen.c index 7df8bc4..aeecef3
>>> 100644 --- a/src/mesa/drivers/dri/i965/intel_screen.c
>>> +++ b/src/mesa/drivers/dri/i965/intel_screen.c
>>> @@ -388,10 +388,16 @@ intel_image_format_lookup(int fourcc)
>>>       return NULL;
>>>    }
>>>    
>>> -static boolean intel_lookup_fourcc(int dri_format, int *fourcc)
>>> +static boolean
>>> +intel_image_get_fourcc(__DRIimage *image, int *fourcc)
>>>    {
>>> +   if (image->planar_format) {
>>> +      *fourcc = image->planar_format->fourcc;
>>> +      return true;
>>> +   }
>>> +
>>>       for (unsigned i = 0; i < ARRAY_SIZE(intel_image_formats); i++)
>>> {
>>> -      if (intel_image_formats[i].planes[0].dri_format ==
>>> dri_format) {
>>> +      if (intel_image_formats[i].planes[0].dri_format ==
>>> image->dri_format) { *fourcc = intel_image_formats[i].fourcc;
>>>             return true;
>>>          }
>>> @@ -844,6 +850,9 @@ intel_create_image_with_modifiers(__DRIscreen
>>> *dri_screen, static GLboolean
>>>    intel_query_image(__DRIimage *image, int attrib, int *value)
>>>    {
>>> +   if (value == NULL)
>>> +      return false;
>>> +
>>
>> I would remove this check, we've been fine many years without it.
> The function spec does say: "<fourcc>, <num_planes> and <modifiers> may
> be NULL, in which case no value is retrieved."
> it's better to stick to it and have an extra check than
> segmentation fault, what do you say?

Function modified here 'intel_query_image' is part of DRI interface 
(dri_interface.h) with no such spec, it is used from many existing 
places and none of them seem to be passing NULL.

Now that I know you are using eglExportDMABUFImageMESA, I can also see 
that dri2_export_dma_buf_image_mesa implementation does not call this 
API when 'fds', 'strides' or 'offsets' is NULL, it checks this in the 
implementation before calling.


>>
>>>       switch (attrib) {
>>>       case __DRI_IMAGE_ATTRIB_STRIDE:
>>>          *value = image->pitch;
>>> @@ -870,7 +879,7 @@ intel_query_image(__DRIimage *image, int
>>> attrib, int *value) case __DRI_IMAGE_ATTRIB_FD:
>>>          return !brw_bo_gem_export_to_prime(image->bo, value);
>>>       case __DRI_IMAGE_ATTRIB_FOURCC:
>>> -      return intel_lookup_fourcc(image->dri_format, value);
>>> +      return intel_image_get_fourcc(image, value);
>>>       case __DRI_IMAGE_ATTRIB_NUM_PLANES:
>>>          if (isl_drm_modifier_has_aux(image->modifier)) {
>>>             assert(!image->planar_format ||
>>> image->planar_format->nplanes == 1);
> 

// Tapani