On Fri, Sep 07, 2018 at 09:32:13AM +0200, Gerd Hoffmann wrote:
> Drivers must set the quirk_addfb_prefer_host_byte_order quirk to make
> the drm_mode_addfb() compat code work correctly on bigendian machines.
>
> If they don't they interpret pixel_format values incorrectly for bug
> compatibility, which in turn implies the ADDFB2 ioctl does not work
> correctly then. So block it to make userspace fallback to ADDFB.
>
> Signed-off-by: Gerd Hoffmann <kraxel@xxxxxxxxxx>
Reviewed-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
> ---
> drivers/gpu/drm/drm_crtc_internal.h | 6 ++++--
> drivers/gpu/drm/drm_framebuffer.c | 24 ++++++++++++++++++++++++
> drivers/gpu/drm/drm_ioctl.c | 2 +-
> 3 files changed, 29 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_crtc_internal.h b/drivers/gpu/drm/drm_crtc_internal.h
> index b613227633..6719e1c8df 100644
> --- a/drivers/gpu/drm/drm_crtc_internal.h
> +++ b/drivers/gpu/drm/drm_crtc_internal.h
> @@ -174,6 +174,8 @@ void drm_fb_release(struct drm_file *file_priv);
>
> int drm_mode_addfb(struct drm_device *dev, struct drm_mode_fb_cmd *or,
> struct drm_file *file_priv);
> +int drm_mode_addfb2(struct drm_device *dev,
> + void *data, struct drm_file *file_priv);
> int drm_mode_rmfb(struct drm_device *dev, u32 fb_id,
> struct drm_file *file_priv);
>
> @@ -181,8 +183,8 @@ int drm_mode_rmfb(struct drm_device *dev, u32 fb_id,
> /* IOCTL */
> int drm_mode_addfb_ioctl(struct drm_device *dev,
> void *data, struct drm_file *file_priv);
> -int drm_mode_addfb2(struct drm_device *dev,
> - void *data, struct drm_file *file_priv);
> +int drm_mode_addfb2_ioctl(struct drm_device *dev,
> + void *data, struct drm_file *file_priv);
> int drm_mode_rmfb_ioctl(struct drm_device *dev,
> void *data, struct drm_file *file_priv);
> int drm_mode_getfb(struct drm_device *dev,
> diff --git a/drivers/gpu/drm/drm_framebuffer.c b/drivers/gpu/drm/drm_framebuffer.c
> index f863f8a20f..fb7528444c 100644
> --- a/drivers/gpu/drm/drm_framebuffer.c
> +++ b/drivers/gpu/drm/drm_framebuffer.c
> @@ -363,6 +363,30 @@ int drm_mode_addfb2(struct drm_device *dev,
> return 0;
> }
>
> +int drm_mode_addfb2_ioctl(struct drm_device *dev,
> + void *data, struct drm_file *file_priv)
> +{
> +#ifdef __BIG_ENDIAN
> + if (!dev->mode_config.quirk_addfb_prefer_host_byte_order) {
> + /*
> + * Drivers must set the
> + * quirk_addfb_prefer_host_byte_order quirk to make
> + * the drm_mode_addfb() compat code work correctly on
> + * bigendian machines.
> + *
> + * If they don't they interpret pixel_format values
> + * incorrectly for bug compatibility, which in turn
> + * implies the ADDFB2 ioctl does not work correctly
> + * then. So block it to make userspace fallback to
> + * ADDFB.
> + */
> + DRM_DEBUG_KMS("addfb2 broken on bigendian");
> + return -EINVAL;
> + }
> +#endif
> + return drm_mode_addfb2(dev, data, file_priv);
> +}
> +
> struct drm_mode_rmfb_work {
> struct work_struct work;
> struct list_head fbs;
> diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
> index ea10e9a26a..6b4a633b42 100644
> --- a/drivers/gpu/drm/drm_ioctl.c
> +++ b/drivers/gpu/drm/drm_ioctl.c
> @@ -645,7 +645,7 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
> DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETPROPBLOB, drm_mode_getblob_ioctl, DRM_UNLOCKED),
> DRM_IOCTL_DEF(DRM_IOCTL_MODE_GETFB, drm_mode_getfb, DRM_UNLOCKED),
> DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB, drm_mode_addfb_ioctl, DRM_UNLOCKED),
> - DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2, DRM_UNLOCKED),
> + DRM_IOCTL_DEF(DRM_IOCTL_MODE_ADDFB2, drm_mode_addfb2_ioctl, DRM_UNLOCKED),
> DRM_IOCTL_DEF(DRM_IOCTL_MODE_RMFB, drm_mode_rmfb_ioctl, DRM_UNLOCKED),
> DRM_IOCTL_DEF(DRM_IOCTL_MODE_PAGE_FLIP, drm_mode_page_flip_ioctl, DRM_MASTER|DRM_UNLOCKED),
> DRM_IOCTL_DEF(DRM_IOCTL_MODE_DIRTYFB, drm_mode_dirtyfb_ioctl, DRM_MASTER|DRM_UNLOCKED),
> --
> 2.9.3
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
_______________________________________________
dri-devel mailing list
dri-devel@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/dri-devel
