[PATCH] usb: dwc3: qcom: Add shutdown callback for dwc3

[PATCH] usb: dwc3: qcom: Add shutdown callback for dwc3

[Sandeep Maheswaram]

This patch adds a shutdown callback to USB DWC QCOM driver to ensure that
it is properly shutdown in reboot/shutdown path. This is required
where SMMU address translation is enabled like on SC7180
SoC and few others. If the hardware is still accessing memory after
SMMU translation is disabled as part of SMMU shutdown callback in
system reboot or shutdown path, then IOVAs(I/O virtual address)
which it was using will go on the bus as the physical addresses which
might result in unknown crashes (NoC/interconnect errors).

Signed-off-by: Sandeep Maheswaram <sanm@codeaurora.org>
---
 drivers/usb/dwc3/dwc3-qcom.c | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
index c703d55..a930e06 100644
--- a/drivers/usb/dwc3/dwc3-qcom.c
+++ b/drivers/usb/dwc3/dwc3-qcom.c
@@ -790,13 +790,11 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int dwc3_qcom_remove(struct platform_device *pdev)
+static void __dwc3_qcom_teardown(struct dwc3_qcom *qcom)
 {
-	struct dwc3_qcom *qcom = platform_get_drvdata(pdev);
-	struct device *dev = &pdev->dev;
 	int i;
 
-	of_platform_depopulate(dev);
+	of_platform_depopulate(qcom->dev);
 
 	for (i = qcom->num_clocks - 1; i >= 0; i--) {
 		clk_disable_unprepare(qcom->clks[i]);
@@ -807,12 +805,27 @@ static int dwc3_qcom_remove(struct platform_device *pdev)
 	dwc3_qcom_interconnect_exit(qcom);
 	reset_control_assert(qcom->resets);
 
-	pm_runtime_allow(dev);
-	pm_runtime_disable(dev);
+	pm_runtime_allow(qcom->dev);
+	pm_runtime_disable(qcom->dev);
+}
+
+static int dwc3_qcom_remove(struct platform_device *pdev)
+{
+	struct dwc3_qcom *qcom = platform_get_drvdata(pdev);
+
+	__dwc3_qcom_teardown(qcom);
 
 	return 0;
 }
 
+static void dwc3_qcom_shutdown(struct platform_device *pdev)
+{
+	struct dwc3_qcom *qcom = platform_get_drvdata(pdev);
+
+	__dwc3_qcom_teardown(qcom);
+
+}
+
 static int __maybe_unused dwc3_qcom_pm_suspend(struct device *dev)
 {
 	struct dwc3_qcom *qcom = dev_get_drvdata(dev);
@@ -887,6 +900,7 @@ MODULE_DEVICE_TABLE(acpi, dwc3_qcom_acpi_match);
 static struct platform_driver dwc3_qcom_driver = {
 	.probe		= dwc3_qcom_probe,
 	.remove		= dwc3_qcom_remove,
+	.shutdown	= dwc3_qcom_shutdown,
 	.driver		= {
 		.name	= "dwc3-qcom",
 		.pm	= &dwc3_qcom_dev_pm_ops,
-- 
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member
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Re: [PATCH] usb: dwc3: qcom: Add shutdown callback for dwc3

[sanm]

On 2020-11-12 12:00, Sandeep Maheswaram wrote:
> This patch adds a shutdown callback to USB DWC QCOM driver to ensure 
> that
> it is properly shutdown in reboot/shutdown path. This is required
> where SMMU address translation is enabled like on SC7180
> SoC and few others. If the hardware is still accessing memory after
> SMMU translation is disabled as part of SMMU shutdown callback in
> system reboot or shutdown path, then IOVAs(I/O virtual address)
> which it was using will go on the bus as the physical addresses which
> might result in unknown crashes (NoC/interconnect errors).
> 
> Signed-off-by: Sandeep Maheswaram <sanm@codeaurora.org>
> ---
>  drivers/usb/dwc3/dwc3-qcom.c | 26 ++++++++++++++++++++------
>  1 file changed, 20 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/usb/dwc3/dwc3-qcom.c 
> b/drivers/usb/dwc3/dwc3-qcom.c
> index c703d55..a930e06 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -790,13 +790,11 @@ static int dwc3_qcom_probe(struct platform_device 
> *pdev)
>  	return ret;
>  }
> 
> -static int dwc3_qcom_remove(struct platform_device *pdev)
> +static void __dwc3_qcom_teardown(struct dwc3_qcom *qcom)
>  {
> -	struct dwc3_qcom *qcom = platform_get_drvdata(pdev);
> -	struct device *dev = &pdev->dev;
>  	int i;
> 
> -	of_platform_depopulate(dev);
> +	of_platform_depopulate(qcom->dev);
> 
>  	for (i = qcom->num_clocks - 1; i >= 0; i--) {
>  		clk_disable_unprepare(qcom->clks[i]);
> @@ -807,12 +805,27 @@ static int dwc3_qcom_remove(struct 
> platform_device *pdev)
>  	dwc3_qcom_interconnect_exit(qcom);
>  	reset_control_assert(qcom->resets);
> 
> -	pm_runtime_allow(dev);
> -	pm_runtime_disable(dev);
> +	pm_runtime_allow(qcom->dev);
> +	pm_runtime_disable(qcom->dev);
> +}
> +
> +static int dwc3_qcom_remove(struct platform_device *pdev)
> +{
> +	struct dwc3_qcom *qcom = platform_get_drvdata(pdev);
> +
> +	__dwc3_qcom_teardown(qcom);
> 
>  	return 0;
>  }
> 
> +static void dwc3_qcom_shutdown(struct platform_device *pdev)
> +{
> +	struct dwc3_qcom *qcom = platform_get_drvdata(pdev);
> +
> +	__dwc3_qcom_teardown(qcom);
> +
> +}
> +
>  static int __maybe_unused dwc3_qcom_pm_suspend(struct device *dev)
>  {
>  	struct dwc3_qcom *qcom = dev_get_drvdata(dev);
> @@ -887,6 +900,7 @@ MODULE_DEVICE_TABLE(acpi, dwc3_qcom_acpi_match);
>  static struct platform_driver dwc3_qcom_driver = {
>  	.probe		= dwc3_qcom_probe,
>  	.remove		= dwc3_qcom_remove,
> +	.shutdown	= dwc3_qcom_shutdown,
>  	.driver		= {
>  		.name	= "dwc3-qcom",
>  		.pm	= &dwc3_qcom_dev_pm_ops,

Hi Felipe,

Can you please review this patch.

Regards
Sandeep

Re: [PATCH] usb: dwc3: qcom: Add shutdown callback for dwc3

[Felipe Balbi]

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Hi,

Sandeep Maheswaram <sanm@codeaurora.org> writes:
> This patch adds a shutdown callback to USB DWC QCOM driver to ensure that
> it is properly shutdown in reboot/shutdown path. This is required
> where SMMU address translation is enabled like on SC7180
> SoC and few others. If the hardware is still accessing memory after
> SMMU translation is disabled as part of SMMU shutdown callback in
> system reboot or shutdown path, then IOVAs(I/O virtual address)
> which it was using will go on the bus as the physical addresses which
> might result in unknown crashes (NoC/interconnect errors).
>
> Signed-off-by: Sandeep Maheswaram <sanm@codeaurora.org>

sounds like this is fixing a bug. Do you have a Fixes tag for it? Should
this go to stable?

> diff --git a/drivers/usb/dwc3/dwc3-qcom.c b/drivers/usb/dwc3/dwc3-qcom.c
> index c703d55..a930e06 100644
> --- a/drivers/usb/dwc3/dwc3-qcom.c
> +++ b/drivers/usb/dwc3/dwc3-qcom.c
> @@ -790,13 +790,11 @@ static int dwc3_qcom_probe(struct platform_device *pdev)
>  	return ret;
>  }
>  
> -static int dwc3_qcom_remove(struct platform_device *pdev)
> +static void __dwc3_qcom_teardown(struct dwc3_qcom *qcom)
>  {
> -	struct dwc3_qcom *qcom = platform_get_drvdata(pdev);
> -	struct device *dev = &pdev->dev;
>  	int i;
>  
> -	of_platform_depopulate(dev);
> +	of_platform_depopulate(qcom->dev);
>  
>  	for (i = qcom->num_clocks - 1; i >= 0; i--) {
>  		clk_disable_unprepare(qcom->clks[i]);
> @@ -807,12 +805,27 @@ static int dwc3_qcom_remove(struct platform_device *pdev)
>  	dwc3_qcom_interconnect_exit(qcom);
>  	reset_control_assert(qcom->resets);
>  
> -	pm_runtime_allow(dev);
> -	pm_runtime_disable(dev);
> +	pm_runtime_allow(qcom->dev);
> +	pm_runtime_disable(qcom->dev);
> +}

you can make the changes smaller by adding:

	struct device *dev = qcom->dev;

The nothing else needs to change in this function ;-)

-- 
balbi

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Re: [PATCH] usb: dwc3: qcom: Add shutdown callback for dwc3

[sanm]

On 2021-01-13 14:10, Felipe Balbi wrote:
> Hi,
> 
> Sandeep Maheswaram <sanm@codeaurora.org> writes:
>> This patch adds a shutdown callback to USB DWC QCOM driver to ensure 
>> that
>> it is properly shutdown in reboot/shutdown path. This is required
>> where SMMU address translation is enabled like on SC7180
>> SoC and few others. If the hardware is still accessing memory after
>> SMMU translation is disabled as part of SMMU shutdown callback in
>> system reboot or shutdown path, then IOVAs(I/O virtual address)
>> which it was using will go on the bus as the physical addresses which
>> might result in unknown crashes (NoC/interconnect errors).
>> 
>> Signed-off-by: Sandeep Maheswaram <sanm@codeaurora.org>
> 
> sounds like this is fixing a bug. Do you have a Fixes tag for it? 
> Should
> this go to stable?
> 
Didn't encounter any bug till now but made this change to prevent issue.

>> diff --git a/drivers/usb/dwc3/dwc3-qcom.c 
>> b/drivers/usb/dwc3/dwc3-qcom.c
>> index c703d55..a930e06 100644
>> --- a/drivers/usb/dwc3/dwc3-qcom.c
>> +++ b/drivers/usb/dwc3/dwc3-qcom.c
>> @@ -790,13 +790,11 @@ static int dwc3_qcom_probe(struct 
>> platform_device *pdev)
>>  	return ret;
>>  }
>> 
>> -static int dwc3_qcom_remove(struct platform_device *pdev)
>> +static void __dwc3_qcom_teardown(struct dwc3_qcom *qcom)
>>  {
>> -	struct dwc3_qcom *qcom = platform_get_drvdata(pdev);
>> -	struct device *dev = &pdev->dev;
>>  	int i;
>> 
>> -	of_platform_depopulate(dev);
>> +	of_platform_depopulate(qcom->dev);
>> 
>>  	for (i = qcom->num_clocks - 1; i >= 0; i--) {
>>  		clk_disable_unprepare(qcom->clks[i]);
>> @@ -807,12 +805,27 @@ static int dwc3_qcom_remove(struct 
>> platform_device *pdev)
>>  	dwc3_qcom_interconnect_exit(qcom);
>>  	reset_control_assert(qcom->resets);
>> 
>> -	pm_runtime_allow(dev);
>> -	pm_runtime_disable(dev);
>> +	pm_runtime_allow(qcom->dev);
>> +	pm_runtime_disable(qcom->dev);
>> +}
> 
> you can make the changes smaller by adding:
> 
> 	struct device *dev = qcom->dev;
> 
> The nothing else needs to change in this function ;-)

I will do this in next version