[PATCH] drm/bridge: dw-hdmi: move cec PA invalidation to dw_hdmi_setup_rx_sense()

[Jonas Karlman]

As an alternative I have a patch [1] to submit that moves cec_notifier_phys_addr_invalidate() call
from dw_hdmi_irq() to dw_hdmi_connector_detect() in order to address an issue with
stale CEC phys addr and stale EDID/ELD data after TV or AVR uses a 100ms HPD pulse
to signal EDID has changed, full patchset at [2].

At the moment CEC phys address is invalidated directly at HPD, leaving the address as invalid
after a 100ms HPD pulse, phys address may later be restored to a valid phys address when
get_modes() is called by drm core.

Should I wait on your and related patches to be merged before submitting my series?

[1] https://github.com/Kwiboo/linux-rockchip/commit/2f4f99c82983e70952668c21f1c56a0241bd75f2
[2] https://github.com/Kwiboo/linux-rockchip/compare/next-20190813...next-20190813-cec-eld

Regards,
Jonas

On 2019-08-13 11:34, Hans Verkuil wrote:
> CC Dariusz as well, since this issue was discovered when testing his
> CEC patches.
>
> Regards,
>
> 	Hans
>
> On 8/13/19 11:32 AM, Hans Verkuil wrote:
>> When testing CEC on the AML-S905X-CC board I noticed that the CEC physical
>> address was not invalidated when the HDMI cable was unplugged. Some more
>> digging showed that meson uses meson_dw_hdmi.c to handle the HPD.
>>
>> Both dw_hdmi_irq() and dw_hdmi_top_thread_irq() (in meson_dw_hdmi.c) call
>> the dw_hdmi_setup_rx_sense() function. So move the code to invalidate the
>> CEC physical address to that function, so that it is independent of where
>> the HPD interrupt happens.
>>
>> Tested with both a AML-S905X-CC and a Khadas VIM2 board.
>>
>> Signed-off-by: Hans Verkuil <hverkuil-cisco at xs4all.nl>
>> ---
>> Note: an alternative would be to make a new dw-hdmi function such as
>> dw_hdmi_cec_phys_addr_invalidate() that is called from meson_dw_hdmi.c.
>> I decided not to do that since this patch is minimally invasive, but
>> that can obviously be changed if that approach is preferred.
>> ---
>> diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> index c5a854af54f8..e899b31e1432 100644
>> --- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> +++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
>> @@ -2329,6 +2329,13 @@ void dw_hdmi_setup_rx_sense(struct dw_hdmi *hdmi, bool hpd, bool rx_sense)
>>  		dw_hdmi_update_power(hdmi);
>>  		dw_hdmi_update_phy_mask(hdmi);
>>  	}
>> +	if (!hpd && !rx_sense) {
>> +		struct cec_notifier *notifier = READ_ONCE(hdmi->cec_notifier);
>> +
>> +		if (notifier)
>> +			cec_notifier_phys_addr_invalidate(notifier);
>> +	}
>> +
>>  	mutex_unlock(&hdmi->mutex);
>>  }
>>  EXPORT_SYMBOL_GPL(dw_hdmi_setup_rx_sense);
>> @@ -2369,14 +2376,6 @@ static irqreturn_t dw_hdmi_irq(int irq, void *dev_id)
>>  		dw_hdmi_setup_rx_sense(hdmi,
>>  				       phy_stat & HDMI_PHY_HPD,
>>  				       phy_stat & HDMI_PHY_RX_SENSE);
>> -
>> -		if ((phy_stat & (HDMI_PHY_RX_SENSE | HDMI_PHY_HPD)) == 0) {
>> -			struct cec_notifier *notifier;
>> -
>> -			notifier = READ_ONCE(hdmi->cec_notifier);
>> -			if (notifier)
>> -				cec_notifier_phys_addr_invalidate(notifier);
>> -		}
>>  	}
>>
>>  	if (intr_stat & HDMI_IH_PHY_STAT0_HPD) {
>>