On 08/04/2017 01:49 AM, Noralf Trønnes wrote:

Den 04.08.2017 00.41, skrev David Lechner:

...

On 08/01/2017 03:14 PM, David Lechner wrote:

...

If we return here and import_attach is true, then dma_buf_end_cpu_access() will not be called balance dma_buf_begin_cpu_access().

Fix by setting ret instead of returning.

Signed-off-by: David Lechner david@lechnology.com

drivers/gpu/drm/tinydrm/mipi-dbi.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/tinydrm/mipi-dbi.c b/drivers/gpu/drm/tinydrm/mipi-dbi.c index c83eeb7..e10fa4b 100644 --- a/drivers/gpu/drm/tinydrm/mipi-dbi.c +++ b/drivers/gpu/drm/tinydrm/mipi-dbi.c @@ -183,7 +183,8 @@ static int mipi_dbi_buf_copy(void *dst, struct drm_framebuffer *fb, dev_err_once(fb->dev->dev, "Format is not supported: %s\n", drm_get_format_name(fb->format->format, &format_name));

•    return -EINVAL;
  

•    ret = -EINVAL;
  

•    break;
  }
    if (import_attach)
  
  

I just realized that the next line here can mask ret.

if (import_attach)
    ret = dma_buf_end_cpu_access(import_attach->dmabuf,
                     DMA_FROM_DEVICE);

So, we should either ignore the return value from dma_buf_end_cpu_access() always or add some logic to ignore it if ret is already an error.

In some of the other patches I have been sending, we have the same situation. I those, I have opted to just ignore the return value from dma_buf_end_cpu_access(). e.g...

if (import_attach)
    dma_buf_end_cpu_access(import_attach->dmabuf, DMA_FROM_DEVICE);

Is this a reasonable thing to do?

mipi_dbi_buf_copy() can be used by other rgb565 controllers, hence the format check I think. So when that happens, it can be moved to tinydrm-helpers.

Currently it's not possible to get an illegal format, since mipi-dbi only supports those two formats. Userspace can't set an illegal format, beacuse it's checked: drm_atomic_commit -> drm_atomic_check_only -> drm_atomic_plane_check -> drm_plane_check_pixel_format

So I think we can just leave this alone, or put the check before import_attach if you really want to put this straight.

I guess we can just leave it alone for now.