Re: [PATCH v2 8/8] drm: zynqmp_dp: Add debugfs interface for compliance testing

From: Sean Anderson
Date: Thu Mar 21 2024 - 12:09:02 EST


On 3/20/24 03:49, Tomi Valkeinen wrote:
> On 20/03/2024 00:51, Sean Anderson wrote:
>
>> +/**
>> + * enum test_pattern - Test patterns for test testing
>
> "for test testing"? =)
>
>> @@ -1655,6 +2321,9 @@ static void zynqmp_dp_hpd_irq_work_func(struct work_struct *work)
>> u8 status[DP_LINK_STATUS_SIZE + 2];
>> int err;
>> + if (READ_ONCE(dp->ignore_hpd))
>> + return;
>> +
>> mutex_lock(&dp->lock);
>> err = drm_dp_dpcd_read(&dp->aux, DP_SINK_COUNT, status,
>> DP_LINK_STATUS_SIZE + 2);
>
> Why do you need READ/WRITE_ONCE() for ignore_hpd?

It's not protected by dp->lock so we don't have to take it for
zynqmp_dp_hpd_work_func. Although maybe we should make a version of
zynqmp_dp_bridge_detect which assumes we already hold the lock.

--Sean