Re: [PATCH v2] drm/bochs: add edid support.

[Dave Airlie]

On Fri, 5 Oct 2018 at 22:10, Gerd Hoffmann <kraxel@xxxxxxxxxx> wrote:
>
> Recent qemu (latest master branch, upcoming 3.1 release) got support
> for EDID data.  This patch adds guest driver support.
>
> EDID support in qemu is not (yet) enabled by default, so please use
> 'qemu -device VGA,edid=on' for testing.

The EDID never changes after boot? Is there plans to let it?
>
> Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
> ---
>  drivers/gpu/drm/bochs/bochs.h     |  1 +
>  drivers/gpu/drm/bochs/bochs_hw.c  | 38 ++++++++++++++++++++++++++++++++++++++
>  drivers/gpu/drm/bochs/bochs_kms.c | 18 +++++++++++++++---
>  3 files changed, 54 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/bochs/bochs.h b/drivers/gpu/drm/bochs/bochs.h
> index e7a69077e4..06b8166efa 100644
> --- a/drivers/gpu/drm/bochs/bochs.h
> +++ b/drivers/gpu/drm/bochs/bochs.h
> @@ -66,6 +66,7 @@ struct bochs_device {
>         u16 yres_virtual;
>         u32 stride;
>         u32 bpp;
> +       struct edid *edid;
>
>         /* drm */
>         struct drm_device  *dev;
> diff --git a/drivers/gpu/drm/bochs/bochs_hw.c b/drivers/gpu/drm/bochs/bochs_hw.c
> index cacff73a64..6ce4cdac38 100644
> --- a/drivers/gpu/drm/bochs/bochs_hw.c
> +++ b/drivers/gpu/drm/bochs/bochs_hw.c
> @@ -69,6 +69,41 @@ static void bochs_hw_set_little_endian(struct bochs_device *bochs)
>  #define bochs_hw_set_native_endian(_b) bochs_hw_set_little_endian(_b)
>  #endif
>
> +static int bochs_load_edid(struct bochs_device *bochs)
> +{
> +       uint8_t *blob;
> +       size_t i, len;
> +       uint8_t num_exts;
> +
> +       if (!bochs->mmio)
> +               return -1;
> +
> +       if ((readb(bochs->mmio+0) != 0x00 ||
> +            readb(bochs->mmio+1) != 0xff))
> +               return -1;
> +
> +       num_exts = readb(bochs->mmio + 126);
> +       len = EDID_LENGTH * (1 + num_exts);
> +       if (len > 0x400 /* vga register offset */)
> +               return -1;
> +
> +       kfree(bochs->edid);
> +       bochs->edid = kmalloc(len, GFP_KERNEL);

Don't you need to free it somewhere?

Dave.