6.16-stable review patch. If anyone has any objections, please let me know.
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From: Thierry Reding treding@nvidia.com
[ Upstream commit cce91f29c088ba902dd2abfc9c3216ba9a2fb2fe ]
Recent generations of Tegra have moved the display components outside of host1x, leading to a device that has no CRTCs attached and hence doesn't support any of the modesetting functionality. When this is detected, the driver clears the DRIVER_MODESET and DRIVER_ATOMIC flags for the device.
Unfortunately, this causes the following errors during boot:
[ 15.418958] ERR KERN drm drm: [drm] *ERROR* Failed to register client: -95 [ 15.425311] WARNING KERN drm drm: [drm] Failed to set up DRM client; error -95
These originate from the fbdev client checking for the presence of the DRIVER_MODESET flag and returning -EOPNOTSUPP. However, if a driver does not support DRIVER_MODESET this is entirely expected and the error isn't helpful.
Prevent this misleading error message by setting up the DRM clients only if modesetting is enabled.
Changes in v2: - use DRIVER_MODESET check to avoid registering any clients
Reported-by: Jonathan Hunter jonathanh@nvidia.com Signed-off-by: Thierry Reding treding@nvidia.com Acked-by: Jon Hunter jonathanh@nvidia.com Tested-by: Jon Hunter jonathanh@nvidia.com Reviewed-by: Thomas Zimmermann tzimmermann@suse.de Link: https://lore.kernel.org/r/20250613122838.2082334-1-thierry.reding@gmail.com Signed-off-by: Dmitry Baryshkov dmitry.baryshkov@oss.qualcomm.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/clients/drm_client_setup.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/clients/drm_client_setup.c b/drivers/gpu/drm/clients/drm_client_setup.c index e17265039ca8..e460ad354de2 100644 --- a/drivers/gpu/drm/clients/drm_client_setup.c +++ b/drivers/gpu/drm/clients/drm_client_setup.c @@ -2,6 +2,7 @@
#include <drm/clients/drm_client_setup.h> #include <drm/drm_device.h> +#include <drm/drm_drv.h> #include <drm/drm_fourcc.h> #include <drm/drm_print.h>
@@ -31,6 +32,10 @@ MODULE_PARM_DESC(active, */ void drm_client_setup(struct drm_device *dev, const struct drm_format_info *format) { + if (!drm_core_check_feature(dev, DRIVER_MODESET)) { + drm_dbg(dev, "driver does not support mode-setting, skipping DRM clients\n"); + return; + }
#ifdef CONFIG_DRM_FBDEV_EMULATION if (!strcmp(drm_client_default, "fbdev")) {