[Mesa-dev] [PATCH 6/5] egl/android: continue to next device if dri2_create_screen fails

[Emil Velikov]

Hi Tomasz,

On 21 August 2018 at 14:54, Tomasz Figa <tfiga at chromium.org> wrote:
> Hi Emil,
>
> On Tue, Aug 14, 2018 at 2:05 AM Emil Velikov <emil.l.velikov at gmail.com> wrote:
>>
>> From: Emil Velikov <emil.velikov at collabora.com>
>>
>> Unlike the other platforms, here we aim do guess if the device that we
>> somewhat arbitrarily picked, is supported or not.
>>
>> It seems a bit fiddly, but considering EGL_EXT_explicit_device and
>> EGL_MESA_query_renderer are MIA, this is the best we can do for the
>> moment.
>>
>> With those (proposed) extensions userspace will be able to create a
>> separate EGL display for each device, query device details and make the
>> conscious decision which one to use.
>>
>> Cc: Robert Foss <robert.foss at collabora.com>
>> Cc: Tomasz Figa <tfiga at chromium.org>
>> Signed-off-by: Emil Velikov <emil.velikov at collabora.com>
>> ---
>>  src/egl/drivers/dri2/platform_android.c | 29 ++++++++++++++++---------
>>  1 file changed, 19 insertions(+), 10 deletions(-)
>>
>> diff --git a/src/egl/drivers/dri2/platform_android.c b/src/egl/drivers/dri2/platform_android.c
>> index 50dd7a5e1b4..cac59847b89 100644
>> --- a/src/egl/drivers/dri2/platform_android.c
>> +++ b/src/egl/drivers/dri2/platform_android.c
>> @@ -1295,6 +1295,25 @@ droid_open_device(_EGLDisplay *disp)
>>           continue;
>>        }
>>        /* Found a device */
>> +
>> +      /* Check that the device is supported, by attempting to:
>> +       * - load the dri module
>> +       * - and, create a screen
>> +       */
>> +      if (!droid_load_driver(disp)) {
>> +         _eglLog(_EGL_WARNING, "DRI2: failed to load driver");
>> +         close(fd);
>> +         fd = -1;
>> +         continue;
>> +      }
>> +
>> +      if (!dri2_create_screen(disp)) {
>> +         _eglLog(_EGL_WARNING, "DRI2: failed to create screen");
>> +         close(fd);
>> +         fd = -1;
>> +         continue;
>> +      }
>
> Don't we also need to do these tests when determining if the device is
> a suitable fallback? The fallback fd is set much earlier, in the same
> block as the continue statement, so the code below wouldn't execute.
>
Let me see if I got this correctly:
 - when a "vendor" is requested we use that, falling back to the first
other driver where screen creation succeeds
 - if one isn't requested, we pick the first device that can create a screen

Is that right?

Thanks
Emil