On Thu, Oct 11, 2012 at 04:27:54PM -0700, Stuart Abercrombie wrote:
> Following a hotplug interrupt the driver uses a successful EDID read to
> indicate HDMI sink presence.
>
> This leads to missing HDMI cable unplug events because the DDC lines can
> remain up, allowing an EDID read to complete, well after the HPD line goes
> down during unplugging
>
> Since it is only the disconnect case that suffers from unplug ordering
> problems with the DDC lines, restrict polling to that. Otherwise we waste
> power.
Nope, the real fix is to simply check the status of the hpd line before
trying the edid read. We already have that for g4x class chips, check
g4x_hdmi_connected. We'd need to add similar checks for all other
platforms.
-Daniel
> ---
> drivers/gpu/drm/drm_crtc_helper.c | 8 ++++++--
> drivers/gpu/drm/i915/intel_hdmi.c | 2 +-
> include/drm/drm_crtc.h | 2 ++
> 3 files changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_crtc_helper.c
> b/drivers/gpu/drm/drm_crtc_helper.c
> index 3252e70..b38ea4f 100644
> --- a/drivers/gpu/drm/drm_crtc_helper.c
> +++ b/drivers/gpu/drm/drm_crtc_helper.c
> @@ -938,8 +938,12 @@ static void output_poll_execute(struct work_struct *work)
> if (!connector->polled)
> continue;
>
> - else if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
> DRM_CONNECTOR_POLL_DISCONNECT))
> - repoll = true;
> + if (connector->polled & (DRM_CONNECTOR_POLL_CONNECT |
> DRM_CONNECTOR_POLL_DISCONNECT)) {
> + if (connector->polled &
> DRM_CONNECTOR_POLL_DISCONNECT_ONLY)
> + repoll = (connector->status ==
> connector_status_connected);
> + else
> + repoll = true;
> + }
>
> old_status = connector->status;
> /* if we are connected and don't want to poll for disconnect
> diff --git a/drivers/gpu/drm/i915/intel_hdmi.c
> b/drivers/gpu/drm/i915/intel_hdmi.c
> index 229897f..246e8f4 100644
> --- a/drivers/gpu/drm/i915/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> @@ -964,7 +964,7 @@ void intel_hdmi_init(struct drm_device *dev, int
> sdvox_reg, enum port port)
>
> intel_encoder->type = INTEL_OUTPUT_HDMI;
>
> - connector->polled = DRM_CONNECTOR_POLL_HPD;
> + connector->polled = DRM_CONNECTOR_POLL_DISCONNECT |
> DRM_CONNECTOR_POLL_DISCONNECT_ONLY;
> connector->interlace_allowed = 1;
> connector->doublescan_allowed = 0;
> intel_encoder->crtc_mask = (1 << 0) | (1 << 1) | (1 << 2);
> diff --git a/include/drm/drm_crtc.h b/include/drm/drm_crtc.h
> index 316ce64..a60abb5 100644
> --- a/include/drm/drm_crtc.h
> +++ b/include/drm/drm_crtc.h
> @@ -503,6 +503,8 @@ enum drm_connector_force {
> /* can cleanly poll for disconnections without flickering the screen */
> /* DACs should rarely do this without a lot of testing */
> #define DRM_CONNECTOR_POLL_DISCONNECT (1 << 2)
> +/* Only poll for disconnections. */
> +#define DRM_CONNECTOR_POLL_DISCONNECT_ONLY (1 << 3)
>
> #define MAX_ELD_BYTES 128
>
> --
> 1.7.7.3
>
> _______________________________________________
> Intel-gfx mailing list
> [email protected]
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch
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