On Wed, Jul 18, 2018 at 04:56:40PM -0400, Lyude Paul wrote:
> For nouveau, while the GPU is guaranteed to be on when a hotplug has
> been received, the same assertion does not hold true if a connector
> probe has been started by userspace without having had received a sysfs
> event.
>
> So ensure that any connector probing keeps the GPU alive for the
> duration of the probe by introducing
> drm_helper_probe_single_connector_modes_with_rpm(). It's the same as
> drm_helper_probe_single_connector_modes, but it handles holding a power
> reference to the device for the duration of the connector probe.
Hm, a runtime PM ref is already acquired in nouveau_connector_detect().
I'm wondering why that's not sufficient?
Thanks,
Lukas
>
> Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>
> Reviewed-by: Karol Herbst <karolherbst@xxxxxxxxx>
> Cc: Lukas Wunner <lukas@xxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> Changes since v1:
> - Add a generic helper to DRM to handle this
>
> drivers/gpu/drm/drm_probe_helper.c | 31 +++++++++++++++++++++
> drivers/gpu/drm/nouveau/dispnv50/disp.c | 2 +-
> drivers/gpu/drm/nouveau/nouveau_connector.c | 4 +--
> include/drm/drm_crtc_helper.h | 7 +++--
> 4 files changed, 38 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c
> index 527743394150..0a9d6748b854 100644
> --- a/drivers/gpu/drm/drm_probe_helper.c
> +++ b/drivers/gpu/drm/drm_probe_helper.c
> @@ -31,6 +31,7 @@
>
> #include <linux/export.h>
> #include <linux/moduleparam.h>
> +#include <linux/pm_runtime.h>
>
> #include <drm/drmP.h>
> #include <drm/drm_crtc.h>
> @@ -541,6 +542,36 @@ int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
> }
> EXPORT_SYMBOL(drm_helper_probe_single_connector_modes);
>
> +/**
> + * drm_helper_probe_single_connector_modes_with_rpm - get complete set of
> + * display modes
> + * @connector: connector to probe
> + * @maxX: max width for modes
> + * @maxY: max height for modes
> + *
> + * Same as drm_helper_probe_single_connector_modes, except that it makes sure
> + * that the device is active by synchronously grabbing a runtime power
> + * reference while probing.
> + *
> + * Returns:
> + * The number of modes found on @connector.
> + */
> +int drm_helper_probe_single_connector_modes_with_rpm(struct drm_connector *connector,
> + uint32_t maxX, uint32_t maxY)
> +{
> + int ret;
> +
> + ret = pm_runtime_get_sync(connector->dev->dev);
> + if (ret < 0 && ret != -EACCES)
> + return ret;
> +
> + ret = drm_helper_probe_single_connector_modes(connector, maxX, maxY);
> +
> + pm_runtime_put(connector->dev->dev);
> + return ret;
> +}
> +EXPORT_SYMBOL(drm_helper_probe_single_connector_modes_with_rpm);
> +
> /**
> * drm_kms_helper_hotplug_event - fire off KMS hotplug events
> * @dev: drm_device whose connector state changed
> diff --git a/drivers/gpu/drm/nouveau/dispnv50/disp.c b/drivers/gpu/drm/nouveau/dispnv50/disp.c
> index fa3ab618a0f9..c54767b50fd8 100644
> --- a/drivers/gpu/drm/nouveau/dispnv50/disp.c
> +++ b/drivers/gpu/drm/nouveau/dispnv50/disp.c
> @@ -858,7 +858,7 @@ static const struct drm_connector_funcs
> nv50_mstc = {
> .reset = nouveau_conn_reset,
> .detect = nv50_mstc_detect,
> - .fill_modes = drm_helper_probe_single_connector_modes,
> + .fill_modes = drm_helper_probe_single_connector_modes_with_rpm,
> .destroy = nv50_mstc_destroy,
> .atomic_duplicate_state = nouveau_conn_atomic_duplicate_state,
> .atomic_destroy_state = nouveau_conn_atomic_destroy_state,
> diff --git a/drivers/gpu/drm/nouveau/nouveau_connector.c b/drivers/gpu/drm/nouveau/nouveau_connector.c
> index 2a45b4c2ceb0..8d9070779261 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_connector.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_connector.c
> @@ -1088,7 +1088,7 @@ nouveau_connector_funcs = {
> .reset = nouveau_conn_reset,
> .detect = nouveau_connector_detect,
> .force = nouveau_connector_force,
> - .fill_modes = drm_helper_probe_single_connector_modes,
> + .fill_modes = drm_helper_probe_single_connector_modes_with_rpm,
> .set_property = nouveau_connector_set_property,
> .destroy = nouveau_connector_destroy,
> .atomic_duplicate_state = nouveau_conn_atomic_duplicate_state,
> @@ -1103,7 +1103,7 @@ nouveau_connector_funcs_lvds = {
> .reset = nouveau_conn_reset,
> .detect = nouveau_connector_detect_lvds,
> .force = nouveau_connector_force,
> - .fill_modes = drm_helper_probe_single_connector_modes,
> + .fill_modes = drm_helper_probe_single_connector_modes_with_rpm,
> .set_property = nouveau_connector_set_property,
> .destroy = nouveau_connector_destroy,
> .atomic_duplicate_state = nouveau_conn_atomic_duplicate_state,
> diff --git a/include/drm/drm_crtc_helper.h b/include/drm/drm_crtc_helper.h
> index 6914633037a5..8f3f6d6fcc8c 100644
> --- a/include/drm/drm_crtc_helper.h
> +++ b/include/drm/drm_crtc_helper.h
> @@ -64,9 +64,10 @@ int drm_helper_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y,
> struct drm_framebuffer *old_fb);
>
> /* drm_probe_helper.c */
> -int drm_helper_probe_single_connector_modes(struct drm_connector
> - *connector, uint32_t maxX,
> - uint32_t maxY);
> +int drm_helper_probe_single_connector_modes(struct drm_connector *connector,
> + uint32_t maxX, uint32_t maxY);
> +int drm_helper_probe_single_connector_modes_with_rpm(struct drm_connector *connector,
> + uint32_t maxX, uint32_t maxY);
> int drm_helper_probe_detect(struct drm_connector *connector,
> struct drm_modeset_acquire_ctx *ctx,
> bool force);
> --
> 2.17.1
>
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