[Intel-gfx] [PATCH] drm/i915: increase the tries for HDMI hotplug live status checking

[Kumar, Shobhit]

On 12/23/2015 01:41 PM, Gary Wang wrote:
> The total delay of HDMI hotplug detecting with 30ms is sometimes not
> enoughtfor HDMI live status up with specific HDMI monitors in BSW platform.
>
> After doing experiments for following monitors, it needs 80ms at least
> for those worst cases.
>
> Lenovo L246 1xwA (4 failed, necessary hot-plug delay: 58/40/60/40ms)
> Philips HH2AP (9 failed, necessary hot-plug delay: 80/50/50/60/46/40/58/58/39ms)
> BENQ ET-0035-N (6 failed, necessary hot-plug delay: 60/50/50/80/80/40ms)
> DELL U2713HM (2 failed, necessary hot-plug delay: 58/59ms)
> HP HP-LP2475w (5 failed, necessary hot-plug delay: 70/50/40/60/40ms)
>
> It looks like 70-80 ms is BSW platform needs in some bad cases of the
> monitors at this end (8 times delay at most). Keep less than 100ms for
> HDCP pulse HPD low (with at least 100ms) to respond a plug out.
>

Tested-by: Shobhit Kumar <shobhit.kumar at intel.com>

Adding
Cc: drm-intel-fixes at lists.freedesktop.org

> Reviewed-by: Cooper Chiou <cooper.chiou at intel.com>
> Tested-by: Gary Wang <gary.c.wang at intel.com>
> Cc: Gavin Hindman <gavin.hindman at intel.com>
> Cc: Sonika Jindal <sonika.jindal at intel.com>
> Cc: Shashank Sharma <shashank.sharma at intel.com>
> Cc: Shobhit Kumar <shobhit.kumar at intel.com>
> Signed-off-by: Gary Wang <gary.c.wang at intel.com>
> ---
>   drivers/gpu/drm/i915/intel_hdmi.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>   mode change 100644 => 100755 drivers/gpu/drm/i915/intel_hdmi.c
>
> diff --git a/drivers/gpu/drm/i915/intel_hdmi.c b/drivers/gpu/drm/i915/intel_hdmi.c
> old mode 100644
> new mode 100755
> index 6214175..4a77639
> --- a/drivers/gpu/drm/i915/intel_hdmi.c
> +++ b/drivers/gpu/drm/i915/intel_hdmi.c
> @@ -1392,7 +1392,7 @@ intel_hdmi_detect(struct drm_connector *connector, bool force)
>
>   	intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS);
>
> -	for (try = 0; !live_status && try < 4; try++) {
> +	for (try = 0; !live_status && try < 9; try++) {
>   		if (try)
>   			msleep(10);
>   		live_status = intel_digital_port_connected(dev_priv,
>