[PATCH] usb: dwc2: do not gate off the hardware if it does not support clock gating

[PATCH] usb: dwc2: do not gate off the hardware if it does not support clock gating

[Dinh Nguyen]

We should not be clearing the HCD_FLAG_HW_ACCESSIBLE bit if the hardware
does not support clock gating.

Fixes: 50fb0c128b6e ("usb: dwc2: Add clock gating entering flow by
system suspend")
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
---
 drivers/usb/dwc2/hcd.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
index 13c779a28e94..f63a27d11fac 100644
--- a/drivers/usb/dwc2/hcd.c
+++ b/drivers/usb/dwc2/hcd.c
@@ -4399,11 +4399,12 @@ static int _dwc2_hcd_suspend(struct usb_hcd *hcd)
 		 * If not hibernation nor partial power down are supported,
 		 * clock gating is used to save power.
 		 */
-		if (!hsotg->params.no_clock_gating)
+		if (!hsotg->params.no_clock_gating) {
 			dwc2_host_enter_clock_gating(hsotg);
 
-		/* After entering suspend, hardware is not accessible */
-		clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
+			/* After entering suspend, hardware is not accessible */
+			clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
+		}
 		break;
 	default:
 		goto skip_power_saving;
-- 
2.25.1

Re: [PATCH] usb: dwc2: do not gate off the hardware if it does not support clock gating

[Minas Harutyunyan]

On 1/4/2022 6:22 AM, Dinh Nguyen wrote:
> We should not be clearing the HCD_FLAG_HW_ACCESSIBLE bit if the hardware
> does not support clock gating.
> 
> Fixes: 50fb0c128b6e ("usb: dwc2: Add clock gating entering flow by
> system suspend")
> Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>


Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>

> ---
>   drivers/usb/dwc2/hcd.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/dwc2/hcd.c b/drivers/usb/dwc2/hcd.c
> index 13c779a28e94..f63a27d11fac 100644
> --- a/drivers/usb/dwc2/hcd.c
> +++ b/drivers/usb/dwc2/hcd.c
> @@ -4399,11 +4399,12 @@ static int _dwc2_hcd_suspend(struct usb_hcd *hcd)
>   		 * If not hibernation nor partial power down are supported,
>   		 * clock gating is used to save power.
>   		 */
> -		if (!hsotg->params.no_clock_gating)
> +		if (!hsotg->params.no_clock_gating) {
>   			dwc2_host_enter_clock_gating(hsotg);
>   
> -		/* After entering suspend, hardware is not accessible */
> -		clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
> +			/* After entering suspend, hardware is not accessible */
> +			clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
> +		}
>   		break;
>   	default:
>   		goto skip_power_saving;

Re: [PATCH] usb: dwc2: do not gate off the hardware if it does not support clock gating

[Sergey Shtylyov]

Hello!

On 1/4/22 5:22 AM, Dinh Nguyen wrote:

> We should not be clearing the HCD_FLAG_HW_ACCESSIBLE bit if the hardware
> does not support clock gating.
> 
> Fixes: 50fb0c128b6e ("usb: dwc2: Add clock gating entering flow by
> system suspend")

   Don't break up this line (perhaps could be fixed while applying).

> Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
[...]

MBR, Sergey

Re: [PATCH] usb: dwc2: do not gate off the hardware if it does not support clock gating

[Dinh Nguyen]

On 1/4/22 3:39 AM, Sergey Shtylyov wrote:
> Hello!
> 
> On 1/4/22 5:22 AM, Dinh Nguyen wrote:
> 
>> We should not be clearing the HCD_FLAG_HW_ACCESSIBLE bit if the hardware
>> does not support clock gating.
>>
>> Fixes: 50fb0c128b6e ("usb: dwc2: Add clock gating entering flow by
>> system suspend")
> 
>     Don't break up this line (perhaps could be fixed while applying).
> 

My bad! Let me re-send.

Dinh