On 2020-04-14 at 15:02:55 -0400, Sean Paul wrote:
> From: Sean Paul <seanpaul@xxxxxxxxxxxx>
>
> The SRM cleanup in 79643fddd6eb2 ("drm/hdcp: optimizing the srm
> handling") inadvertently altered the behavior of HDCP auth when
> the SRM firmware is missing. Before that patch, missing SRM was
> interpreted as the device having no revoked keys. With that patch,
> if the SRM fw file is missing we reject _all_ keys.
>
> This patch fixes that regression by returning success if the file
> cannot be found. It also checks the return value from request_srm such
> that we won't end up trying to parse the ksv list if there is an error
> fetching it.
>
> Fixes: 79643fddd6eb ("drm/hdcp: optimizing the srm handling")
> Cc: stable@xxxxxxxxxxxxxxx
> Cc: Ramalingam C <ramalingam.c@xxxxxxxxx>
> Cc: Sean Paul <sean@xxxxxxxxxx>
> Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> Cc: Maxime Ripard <mripard@xxxxxxxxxx>
> Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
> Cc: David Airlie <airlied@xxxxxxxx>
> Cc: Daniel Vetter <daniel@xxxxxxxx>
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Sean Paul <seanpaul@xxxxxxxxxxxx>
>
> Changes in v2:
> -Noticed a couple other things to clean up
> ---
>
> Sorry for the quick rev, noticed a couple other loose ends that should
> be cleaned up.
>
> drivers/gpu/drm/drm_hdcp.c | 8 +++++++-
> 1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_hdcp.c b/drivers/gpu/drm/drm_hdcp.c
> index 7f386adcf872..910108ccaae1 100644
> --- a/drivers/gpu/drm/drm_hdcp.c
> +++ b/drivers/gpu/drm/drm_hdcp.c
> @@ -241,8 +241,12 @@ static int drm_hdcp_request_srm(struct drm_device *drm_dev,
>
> ret = request_firmware_direct(&fw, (const char *)fw_name,
> drm_dev->dev);
> - if (ret < 0)
> + if (ret < 0) {
> + *revoked_ksv_cnt = 0;
> + *revoked_ksv_list = NULL;
These two variables are already initialized by the caller.
> + ret = 0;
Missing of this should have been caught by CI. May be CI system always
having the SRM file from previous execution. Never been removed. IGT
need a fix to clean the prior SRM files before execution.
CI fix shouldn't block this fix.
> goto exit;
> + }
>
> if (fw->size && fw->data)
> ret = drm_hdcp_srm_update(fw->data, fw->size, revoked_ksv_list,
> @@ -287,6 +291,8 @@ int drm_hdcp_check_ksvs_revoked(struct drm_device *drm_dev, u8 *ksvs,
>
> ret = drm_hdcp_request_srm(drm_dev, &revoked_ksv_list,
> &revoked_ksv_cnt);
> + if (ret)
> + return ret;
This error code also shouldn't effect the caller(i915) hence pushed a
change https://patchwork.freedesktop.org/series/76730/
With these addresed.
LGTM.
Reviewed-by: Ramalingam C <ramalingam.c@xxxxxxxxx>
>
> /* revoked_ksv_cnt will be zero when above function failed */
> for (i = 0; i < revoked_ksv_cnt; i++)
> --
> Sean Paul, Software Engineer, Google / Chromium OS
>
