Re: [PATCH v1] drm/msm/dp: use dp_hpd_plug_handle() and dp_hpd_unplug_handle() directly

From: Abhinav Kumar
Date: Thu Mar 28 2024 - 17:21:42 EST




On 3/28/2024 1:58 PM, Stephen Boyd wrote:
Quoting Abhinav Kumar (2024-03-28 13:24:34)
+ Johan and Bjorn for FYI

On 3/28/2024 1:04 PM, Kuogee Hsieh wrote:
For internal HPD case, hpd_event_thread is created to handle HPD
interrupts generated by HPD block of DP controller. It converts
HPD interrupts into events and executed them under hpd_event_thread
context. For external HPD case, HPD events is delivered by way of
dp_bridge_hpd_notify() under thread context. Since they are executed
under thread context already, there is no reason to hand over those
events to hpd_event_thread. Hence dp_hpd_plug_handle() and
dp_hpd_unplug_hanlde() are called directly at dp_bridge_hpd_notify().

Signed-off-by: Kuogee Hsieh <quic_khsieh@xxxxxxxxxxx>
---
drivers/gpu/drm/msm/dp/dp_display.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)


Fixes: 542b37efc20e ("drm/msm/dp: Implement hpd_notify()")

Is this a bug fix or an optimization? The commit text doesn't tell me.


I would say both.

optimization as it avoids the need to go through the hpd_event thread processing.

bug fix because once you go through the hpd event thread processing it exposes and often breaks the already fragile hpd handling state machine which can be avoided in this case.


Looks right to me,

Reviewed-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>