Re: [PATCH] drm: bridge: dw-hdmi: Avoid resetting force in the detect function

[Sam Ravnborg]

Hi Russell,

On Sun, Nov 08, 2020 at 09:57:25AM +0000, Russell King - ARM Linux admin wrote:
> On Sun, Nov 08, 2020 at 10:53:22AM +0100, Sam Ravnborg wrote:
> > Russell,
> > 
> > On Sat, Oct 31, 2020 at 07:17:47PM +1100, Jonathan Liu wrote:
> > > It has been observed that resetting force in the detect function can
> > > result in the PHY being powered down in response to hot-plug detect
> > > being asserted, even when the HDMI connector is forced on.
> > > 
> > > Enabling debug messages and adding a call to dump_stack() in
> > > dw_hdmi_phy_power_off() shows the following in dmesg:
> > > [  160.637413] dwhdmi-rockchip ff940000.hdmi: EVENT=plugin
> > > [  160.637433] dwhdmi-rockchip ff940000.hdmi: PHY powered down in 0 iterations
> > > 
> > > Call trace:
> > > dw_hdmi_phy_power_off
> > > dw_hdmi_phy_disable
> > > dw_hdmi_update_power
> > > dw_hdmi_detect
> > > dw_hdmi_connector_detect
> > > drm_helper_probe_detect_ctx
> > > drm_helper_hpd_irq_event
> > > dw_hdmi_irq
> > > irq_thread_fn
> > > irq_thread
> > > kthread
> > > ret_from_fork
> > > 
> > > Fixes: 381f05a7a842 ("drm: bridge/dw_hdmi: add connector mode forcing")
> > > Signed-off-by: Jonathan Liu <net147@xxxxxxxxx>
> > 
> > you are the original author of this code - any comments on this patch?
> 
> No further comments beyond what has already been discussed, and the
> long and short of it is it's been so long that I don't remember why
> that code was there. Given that, I'm not even in a position to ack
> the change. Sorry.
Thanks for the quick reply.

Given that this fixes a problem for Jonathan I will apply this to -fixes
if there is no other feedback the next couple of days.
If it introduces regression we can take it from there.

Jonathan - please ping me if I forget.

	Sam