Re: [PATCH] drm/bridge: adv7511: Clear HPD IRQ before powering on device during resume()

[Tommaso Merciai]

Hi Biju,
Thanks for your patch!

On Fri, Dec 19, 2025 at 10:46:53AM +0000, Biju wrote:
> From: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> 
> On RZ/G3E SMARC EVK using PSCI, s2ram powers down the SoC. Testing ADV7535
> IRQ configured as edge-triggered interrupt on RZ/G3E SMARC EVK shows that
> it is missing HPD IRQ during system resume, as the status change occurs
> before the IRQ/pincontrol resume. Once the status bit is set, there won't
> be any further IRQ unless the status bit is cleared.
> 
> Clear any pending HPD IRQs before powering on the ADV7535 device to
> deliver HPD interrupts after resume().
> 

Tested-by: Tommaso Merciai <tommaso.merciai.xr@xxxxxxxxxxxxxx>
Reviewed-by: Tommaso Merciai <tommaso.merciai.xr@xxxxxxxxxxxxxx>

> Signed-off-by: Biju Das <biju.das.jz@xxxxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/bridge/adv7511/adv7511.h     |  1 +
>  drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 32 ++++++++++++++++++++
>  2 files changed, 33 insertions(+)
> 
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511.h b/drivers/gpu/drm/bridge/adv7511/adv7511.h
> index 8be7266fd4f4..03aa23836ca4 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7511.h
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7511.h
> @@ -393,6 +393,7 @@ struct adv7511 {
>  	bool cec_enabled_adap;
>  	struct clk *cec_clk;
>  	u32 cec_clk_freq;
> +	bool suspended;
>  };
>  
>  static inline struct adv7511 *bridge_to_adv7511(struct drm_bridge *bridge)
> diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> index b9be86541307..8d9467187d7c 100644
> --- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> +++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
> @@ -790,6 +790,25 @@ static void adv7511_bridge_atomic_enable(struct drm_bridge *bridge,
>  	struct drm_connector_state *conn_state;
>  	struct drm_crtc_state *crtc_state;
>  
> +	if (adv->i2c_main->irq && adv->suspended) {
> +		unsigned int irq;
> +
> +		/*
> +		 * If ADV7511 IRQ is configured as edge triggered interrupt, it
> +		 * will miss the IRQ during system resume as the status change
> +		 * occurs before IRQ/pincontrol resume. Once the status bit is
> +		 * set there won't be any further IRQ unless the status bit is
> +		 * cleared. So, clear the IRQ status bit for further delivery
> +		 * of HPD IRQ.
> +		 */
> +		regmap_read(adv->regmap, ADV7511_REG_INT(0), &irq);
> +		if (irq & ADV7511_INT0_HPD)
> +			regmap_write(adv->regmap, ADV7511_REG_INT(0),
> +				     ADV7511_INT0_HPD);
> +
> +		adv->suspended = false;
> +	}
> +
>  	adv7511_power_on(adv);
>  
>  	connector = drm_atomic_get_new_connector_for_encoder(state, bridge->encoder);
> @@ -1407,6 +1426,16 @@ static void adv7511_remove(struct i2c_client *i2c)
>  	i2c_unregister_device(adv7511->i2c_edid);
>  }
>  
> +static int adv7511_suspend(struct device *dev)
> +{
> +	struct i2c_client *i2c = to_i2c_client(dev);
> +	struct adv7511 *adv7511 = i2c_get_clientdata(i2c);
> +
> +	adv7511->suspended = true;
> +
> +	return 0;
> +}
> +
>  static const struct adv7511_chip_info adv7511_chip_info = {
>  	.type = ADV7511,
>  	.name = "ADV7511",
> @@ -1439,6 +1468,8 @@ static const struct adv7511_chip_info adv7535_chip_info = {
>  	.hpd_override_enable = true,
>  };
>  
> +static DEFINE_SIMPLE_DEV_PM_OPS(adv7511_pm_ops, adv7511_suspend, NULL);
> +
>  static const struct i2c_device_id adv7511_i2c_ids[] = {
>  	{ "adv7511", (kernel_ulong_t)&adv7511_chip_info },
>  	{ "adv7511w", (kernel_ulong_t)&adv7511_chip_info },
> @@ -1467,6 +1498,7 @@ static struct i2c_driver adv7511_driver = {
>  	.driver = {
>  		.name = "adv7511",
>  		.of_match_table = adv7511_of_ids,
> +		.pm = pm_sleep_ptr(&adv7511_pm_ops),
>  	},
>  	.id_table = adv7511_i2c_ids,
>  	.probe = adv7511_probe,
> -- 
> 2.43.0
>

Kind Regards,
Tommaso