Hi John,
Thank you for the patch.
On Tuesday 03 Jan 2017 11:41:39 John Stultz wrote:
> In chasing down a previous issue with EDID probing from calling
> drm_helper_hpd_irq_event() from irq context, Laurent noticed
> that the DRM documentation suggests that
> drm_kms_helper_hotplug_event() should be used instead.
>
> Thus this patch replaces drm_helper_hpd_irq_event() with
> drm_kms_helper_hotplug_event(), which requires we update the
> connector.status entry and only call _hotplug_event() when the
> status changes.
>
> Cc: David Airlie <airlied@xxxxxxxx>
> Cc: Archit Taneja <architt@xxxxxxxxxxxxxx>
> Cc: Wolfram Sang <wsa+renesas@xxxxxxxxxxxxxxxxxxxx>
> Cc: Lars-Peter Clausen <lars@xxxxxxxxxx>
> Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: John Stultz <john.stultz@xxxxxxxxxx>
> ---
> v3: Update connector.status value and only call __hotplug_event()
> when that status changes, as suggested by Laurent.
>
> drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 16 +++++++++++++++-
> 1 file changed, 15 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c index 4fcea44..d93d66f
> 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> @@ -405,8 +405,22 @@ static bool adv7511_hpd(struct adv7511 *adv7511)
> static void adv7511_hpd_work(struct work_struct *work)
> {
> struct adv7511 *adv7511 = container_of(work, struct adv7511,
hpd_work);
> + enum drm_connector_status status;
> + unsigned int val;
> + int ret;
> +
> + ret = regmap_read(adv7511->regmap, ADV7511_REG_STATUS, &val);
> + if (ret < 0)
> + status = connector_status_disconnected;
> + else if (val & ADV7511_STATUS_HPD)
> + status = connector_status_connected;
> + else
> + status = connector_status_disconnected;
> +
> + if (adv7511->connector.status != status)
> + drm_kms_helper_hotplug_event(adv7511->connector.dev);
>
> - drm_helper_hpd_irq_event(adv7511->connector.dev);
> + adv7511->connector.status = status;
Shouldn't you update the status before calling drm_kms_helper_hotplug_event()
? Doing it after not only creates a small race condition as
drm_kms_helper_hotplug_event() sends an event to userspace that could result
in an ioctl call to retrieve the status, but the status is also checked by
drm_setup_crtcs() called by drm_fb_helper_hotplug_event().
> }
>
> static int adv7511_irq_process(struct adv7511 *adv7511, bool process_hpd)
--
Regards,
Laurent Pinchart
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