[Intel-gfx] [PATCH] drm/i915: storm detection documentation update

[Daniel Vetter]

On Tue, Jul 07, 2015 at 04:10:49PM +0530, Sivakumar Thulasimani wrote:
> From: "Thulasimani,Sivakumar" <sivakumar.thulasimani at intel.com>
> 
> Update the hotplug documentation to explain that hotplug storm
> is not expected for Display port panels and hence is not handled
> in current code.
> 
> Signed-off-by: Sivakumar Thulasimani <sivakumar.thulasimani at intel.com>
> ---
>  drivers/gpu/drm/i915/intel_hotplug.c |    4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_hotplug.c b/drivers/gpu/drm/i915/intel_hotplug.c
> index bac91a1..7dc5e6a 100644
> --- a/drivers/gpu/drm/i915/intel_hotplug.c
> +++ b/drivers/gpu/drm/i915/intel_hotplug.c
> @@ -66,6 +66,10 @@
>   * while before being re-enabled. The intention is to mitigate issues raising
>   * from broken hardware triggering massive amounts of interrupts and grinding
>   * the system to a halt.
> + *
> + * Hotplug interrupt storm is not expected on Display port panel, hence the
> + * current code only handles disabling and later enabling of HPD interrupts
> + * for HDMI panels through the storm handling set of functions.

This isn't accurate, we handle storms on everything _but_ DP (tv, vga,
sdvo, ...). I'd go with

 * Hotplug interrupt storm is not expected on Display port panel, hence the
 * current code doesn't handle irq reenabling when a DP sink is connected
 * and the hpd is handled by the DP callbacks. But on DP+ ports
 * storms are still handled correctly in all other cases (e.g. due to HDMI
 * sinks).

Could still be improved I think.

-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch