[PATCH v 4] usb: dwc2: gadget: Fix enter to hibernation for UTMI+ PHY

[PATCH v 4] usb: dwc2: gadget: Fix enter to hibernation for UTMI+ PHY

[Minas Harutyunyan]

For UTMI+ PHY, according to programming guide, first should be set
PMUACTV bit then STOPPCLK bit. Otherwise, when the device issues
Remote Wakeup, then host notices disconnect instead.
For ULPI PHY, above mentioned bits must be set in reversed order:
STOPPCLK then PMUACTV.

Fixes: 4483ef3c1685 ("usb: dwc2: Add hibernation updates for ULPI PHY")
Cc: stable@vger.kernel.org
Reported-by: Tomasz Mon <tomasz.mon@nordicsemi.no>
Signed-off-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
---
 Changes in v4:
 - Rebased on top of Linux 6.15-rc6
 Changes in v3:
 - Rebased on top of 6.15-rc4
 Changes in v2:
 - Added Cc: stable@vger.kernel.org

 drivers/usb/dwc2/gadget.c | 37 +++++++++++++++++++++++++------------
 1 file changed, 25 insertions(+), 12 deletions(-)

diff --git a/drivers/usb/dwc2/gadget.c b/drivers/usb/dwc2/gadget.c
index 300ea4969f0c..b817002bdee0 100644
--- a/drivers/usb/dwc2/gadget.c
+++ b/drivers/usb/dwc2/gadget.c
@@ -5383,20 +5383,33 @@ int dwc2_gadget_enter_hibernation(struct dwc2_hsotg *hsotg)
        if (gusbcfg & GUSBCFG_ULPI_UTMI_SEL) {
                /* ULPI interface */
                gpwrdn |= GPWRDN_ULPI_LATCH_EN_DURING_HIB_ENTRY;
-       }
-       dwc2_writel(hsotg, gpwrdn, GPWRDN);
-       udelay(10);
+               dwc2_writel(hsotg, gpwrdn, GPWRDN);
+               udelay(10);

-       /* Suspend the Phy Clock */
-       pcgcctl = dwc2_readl(hsotg, PCGCTL);
-       pcgcctl |= PCGCTL_STOPPCLK;
-       dwc2_writel(hsotg, pcgcctl, PCGCTL);
-       udelay(10);
+               pcgcctl = dwc2_readl(hsotg, PCGCTL);
+               pcgcctl |= PCGCTL_STOPPCLK;
+               dwc2_writel(hsotg, pcgcctl, PCGCTL);
+               udelay(10);

-       gpwrdn = dwc2_readl(hsotg, GPWRDN);
-       gpwrdn |= GPWRDN_PMUACTV;
-       dwc2_writel(hsotg, gpwrdn, GPWRDN);
-       udelay(10);
+               gpwrdn = dwc2_readl(hsotg, GPWRDN);
+               gpwrdn |= GPWRDN_PMUACTV;
+               dwc2_writel(hsotg, gpwrdn, GPWRDN);
+               udelay(10);
+       } else {
+               /* UTMI+ Interface */
+               dwc2_writel(hsotg, gpwrdn, GPWRDN);
+               udelay(10);
+
+               gpwrdn = dwc2_readl(hsotg, GPWRDN);
+               gpwrdn |= GPWRDN_PMUACTV;
+               dwc2_writel(hsotg, gpwrdn, GPWRDN);
+               udelay(10);
+
+               pcgcctl = dwc2_readl(hsotg, PCGCTL);
+               pcgcctl |= PCGCTL_STOPPCLK;
+               dwc2_writel(hsotg, pcgcctl, PCGCTL);
+               udelay(10);
+       }

        /* Set flag to indicate that we are in hibernation */
        hsotg->hibernated = 1;

--
2.41.0

Re: [PATCH v 4] usb: dwc2: gadget: Fix enter to hibernation for UTMI+ PHY

[Greg Kroah-Hartman]

On Tue, Jun 03, 2025 at 07:16:32AM +0000, Minas Harutyunyan wrote:
> For UTMI+ PHY, according to programming guide, first should be set
> PMUACTV bit then STOPPCLK bit. Otherwise, when the device issues
> Remote Wakeup, then host notices disconnect instead.
> For ULPI PHY, above mentioned bits must be set in reversed order:
> STOPPCLK then PMUACTV.
> 
> Fixes: 4483ef3c1685 ("usb: dwc2: Add hibernation updates for ULPI PHY")
> Cc: stable@vger.kernel.org
> Reported-by: Tomasz Mon <tomasz.mon@nordicsemi.no>
> Signed-off-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
> ---
>  Changes in v4:
>  - Rebased on top of Linux 6.15-rc6
>  Changes in v3:
>  - Rebased on top of 6.15-rc4
>  Changes in v2:
>  - Added Cc: stable@vger.kernel.org
> 
>  drivers/usb/dwc2/gadget.c | 37 +++++++++++++++++++++++++------------
>  1 file changed, 25 insertions(+), 12 deletions(-)

Fails to apply on top of 6.16-rc2 :(