Re: [PATCH v3] drm/bochs: add edid present check

[Oleksandr Andrushchenko]

On 12/20/18 12:51 PM, Daniel Vetter wrote:

On Thu, Dec 20, 2018 at 11:11:21AM +0100, Gerd Hoffmann wrote:

Check header before trying to read the complete edid blob, to avoid the
log being spammed in case qemu has no edid support (old qemu or edid
support turned off).

Fixes: 01f23459cf drm/bochs: add edid support.
Signed-off-by: Gerd Hoffmann 

Reviewed-by: Daniel Vetter 

Reviewed-by: Oleksandr Andrushchenko 



---
  drivers/gpu/drm/bochs/bochs_hw.c | 7 +++
  1 file changed, 7 insertions(+)

diff --git a/drivers/gpu/drm/bochs/bochs_hw.c b/drivers/gpu/drm/bochs/bochs_hw.c
index c90a0d492f..d0b4e1cee8 100644
--- a/drivers/gpu/drm/bochs/bochs_hw.c
+++ b/drivers/gpu/drm/bochs/bochs_hw.c
@@ -86,9 +86,16 @@ static int bochs_get_edid_block(void *data, u8 *buf,
  
  int bochs_hw_load_edid(struct bochs_device *bochs)

  {
+   u8 header[8];
+
if (!bochs->mmio)
return -1;
  
+	/* check header to detect whenever edid support is enabled in qemu */

+   bochs_get_edid_block(bochs, header, 0, ARRAY_SIZE(header));
+   if (drm_edid_header_is_valid(header) != 8)
+   return -1;
+
kfree(bochs->edid);
bochs->edid = drm_do_get_edid(>connector,
  bochs_get_edid_block, bochs);
--
2.9.3

Re: [PATCH v3] drm/bochs: add edid present check

[Daniel Vetter]

On Thu, Dec 20, 2018 at 11:11:21AM +0100, Gerd Hoffmann wrote:
> Check header before trying to read the complete edid blob, to avoid the
> log being spammed in case qemu has no edid support (old qemu or edid
> support turned off).
> 
> Fixes: 01f23459cf drm/bochs: add edid support.
> Signed-off-by: Gerd Hoffmann 

Reviewed-by: Daniel Vetter 

> ---
>  drivers/gpu/drm/bochs/bochs_hw.c | 7 +++
>  1 file changed, 7 insertions(+)
> 
> diff --git a/drivers/gpu/drm/bochs/bochs_hw.c 
> b/drivers/gpu/drm/bochs/bochs_hw.c
> index c90a0d492f..d0b4e1cee8 100644
> --- a/drivers/gpu/drm/bochs/bochs_hw.c
> +++ b/drivers/gpu/drm/bochs/bochs_hw.c
> @@ -86,9 +86,16 @@ static int bochs_get_edid_block(void *data, u8 *buf,
>  
>  int bochs_hw_load_edid(struct bochs_device *bochs)
>  {
> + u8 header[8];
> +
>   if (!bochs->mmio)
>   return -1;
>  
> + /* check header to detect whenever edid support is enabled in qemu */
> + bochs_get_edid_block(bochs, header, 0, ARRAY_SIZE(header));
> + if (drm_edid_header_is_valid(header) != 8)
> + return -1;
> +
>   kfree(bochs->edid);
>   bochs->edid = drm_do_get_edid(>connector,
> bochs_get_edid_block, bochs);
> -- 
> 2.9.3
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch