diff mbox series

[v2,2/7] phy: qcom: qmp-combo: store DP phy power state

Message ID 20240527-topic-sm8x50-upstream-phy-combo-typec-mux-v2-2-a03e68d7b8fc@linaro.org (mailing list archive)
State Not Applicable
Headers show
Series arm64: qcom: allow up to 4 lanes for the Type-C DisplayPort Altmode | expand

Commit Message

Neil Armstrong May 27, 2024, 8:42 a.m. UTC
Switching the PHY Mode requires the DisplayPort PHY to be powered off,
keep track of the DisplayPort phy power state.

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Dmitry Baryshkov May 27, 2024, 8:59 a.m. UTC | #1
On Mon, May 27, 2024 at 10:42:34AM +0200, Neil Armstrong wrote:
> Switching the PHY Mode requires the DisplayPort PHY to be powered off,
> keep track of the DisplayPort phy power state.

How is this different from dp_init_count?

> 
> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
> ---
>  drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
> index 7f999e8a433d..183cd9cd1884 100644
> --- a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
> @@ -1512,6 +1512,7 @@ struct qmp_combo {
>  	unsigned int dp_aux_cfg;
>  	struct phy_configure_opts_dp dp_opts;
>  	unsigned int dp_init_count;
> +	bool dp_powered_on;
>  
>  	struct clk_fixed_rate pipe_clk_fixed;
>  	struct clk_hw dp_link_hw;
> @@ -2685,6 +2686,8 @@ static int qmp_combo_dp_power_on(struct phy *phy)
>  	/* Configure link rate, swing, etc. */
>  	cfg->configure_dp_phy(qmp);
>  
> +	qmp->dp_powered_on = true;
> +
>  	mutex_unlock(&qmp->phy_mutex);
>  
>  	return 0;
> @@ -2699,6 +2702,8 @@ static int qmp_combo_dp_power_off(struct phy *phy)
>  	/* Assert DP PHY power down */
>  	writel(DP_PHY_PD_CTL_PSR_PWRDN, qmp->dp_dp_phy + QSERDES_DP_PHY_PD_CTL);
>  
> +	qmp->dp_powered_on = false;
> +
>  	mutex_unlock(&qmp->phy_mutex);
>  
>  	return 0;
> 
> -- 
> 2.34.1
>
Neil Armstrong June 6, 2024, 1:29 p.m. UTC | #2
On 27/05/2024 10:59, Dmitry Baryshkov wrote:
> On Mon, May 27, 2024 at 10:42:34AM +0200, Neil Armstrong wrote:
>> Switching the PHY Mode requires the DisplayPort PHY to be powered off,
>> keep track of the DisplayPort phy power state.
> 
> How is this different from dp_init_count?

dp_init_count tracks the DP PHY init, while dp_powered_on tracks
the DP PHY beeing powered on by the DRM DP driver, those are
not the same state at all.

While testing, I figured that de-initializing the DP PHY while
is was powered-on by the DRM DP, caused the system to freeze and crash.

SO I've added this to track this state and try to de-init the DP phy
if still in use.

Neil

> 
>>
>> Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
>> ---
>>   drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 5 +++++
>>   1 file changed, 5 insertions(+)
>>
>> diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
>> index 7f999e8a433d..183cd9cd1884 100644
>> --- a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
>> +++ b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
>> @@ -1512,6 +1512,7 @@ struct qmp_combo {
>>   	unsigned int dp_aux_cfg;
>>   	struct phy_configure_opts_dp dp_opts;
>>   	unsigned int dp_init_count;
>> +	bool dp_powered_on;
>>   
>>   	struct clk_fixed_rate pipe_clk_fixed;
>>   	struct clk_hw dp_link_hw;
>> @@ -2685,6 +2686,8 @@ static int qmp_combo_dp_power_on(struct phy *phy)
>>   	/* Configure link rate, swing, etc. */
>>   	cfg->configure_dp_phy(qmp);
>>   
>> +	qmp->dp_powered_on = true;
>> +
>>   	mutex_unlock(&qmp->phy_mutex);
>>   
>>   	return 0;
>> @@ -2699,6 +2702,8 @@ static int qmp_combo_dp_power_off(struct phy *phy)
>>   	/* Assert DP PHY power down */
>>   	writel(DP_PHY_PD_CTL_PSR_PWRDN, qmp->dp_dp_phy + QSERDES_DP_PHY_PD_CTL);
>>   
>> +	qmp->dp_powered_on = false;
>> +
>>   	mutex_unlock(&qmp->phy_mutex);
>>   
>>   	return 0;
>>
>> -- 
>> 2.34.1
>>
>
Dmitry Baryshkov June 7, 2024, 7:32 a.m. UTC | #3
On Thu, Jun 06, 2024 at 03:29:52PM +0200, Neil Armstrong wrote:
> On 27/05/2024 10:59, Dmitry Baryshkov wrote:
> > On Mon, May 27, 2024 at 10:42:34AM +0200, Neil Armstrong wrote:
> > > Switching the PHY Mode requires the DisplayPort PHY to be powered off,
> > > keep track of the DisplayPort phy power state.
> > 
> > How is this different from dp_init_count?
> 
> dp_init_count tracks the DP PHY init, while dp_powered_on tracks
> the DP PHY beeing powered on by the DRM DP driver, those are
> not the same state at all.
> 
> While testing, I figured that de-initializing the DP PHY while
> is was powered-on by the DRM DP, caused the system to freeze and crash.
> 
> SO I've added this to track this state and try to de-init the DP phy
> if still in use.

If you are to send next iteration, please add these bits to the commit
message.

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
diff mbox series

Patch

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
index 7f999e8a433d..183cd9cd1884 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
@@ -1512,6 +1512,7 @@  struct qmp_combo {
 	unsigned int dp_aux_cfg;
 	struct phy_configure_opts_dp dp_opts;
 	unsigned int dp_init_count;
+	bool dp_powered_on;
 
 	struct clk_fixed_rate pipe_clk_fixed;
 	struct clk_hw dp_link_hw;
@@ -2685,6 +2686,8 @@  static int qmp_combo_dp_power_on(struct phy *phy)
 	/* Configure link rate, swing, etc. */
 	cfg->configure_dp_phy(qmp);
 
+	qmp->dp_powered_on = true;
+
 	mutex_unlock(&qmp->phy_mutex);
 
 	return 0;
@@ -2699,6 +2702,8 @@  static int qmp_combo_dp_power_off(struct phy *phy)
 	/* Assert DP PHY power down */
 	writel(DP_PHY_PD_CTL_PSR_PWRDN, qmp->dp_dp_phy + QSERDES_DP_PHY_PD_CTL);
 
+	qmp->dp_powered_on = false;
+
 	mutex_unlock(&qmp->phy_mutex);
 
 	return 0;