diff mbox series

[6/6] usb: dwc3: gadget: Disable GUSB2PHYCFG.SUSPHY for End Transfer

Message ID 20240412202611.3565052-7-alexander.sverdlin@siemens.com
State New
Delegated to: Marek Vasut
Headers show
Series usb: dwc3: gadget: avoid EP command timeout | expand

Commit Message

Sverdlin, Alexander April 12, 2024, 8:26 p.m. UTC 
From: Thinh Nguyen <Thinh.Nguyen@synopsys.com>

Upstream Linux commit 3aa07f72894d.

If there's a disconnection while operating in eSS, there may be a delay
in VBUS drop response from the connector. In that case, the internal
link state may drop to operate in usb2 speed while the controller thinks
the VBUS is still high. The driver must make sure to disable
GUSB2PHYCFG.SUSPHY when sending endpoint command while in usb2 speed.
The End Transfer command may be called, and only that command needs to
go through at this point. Let's keep it simple and unconditionally
disable GUSB2PHYCFG.SUSPHY whenever we issue the command.

This scenario is not seen in real hardware. In a rare case, our
prototype type-c controller/interface may have a slow response
triggerring this issue.

Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/5651117207803c26e2f22ddf4e5ce9e865dcf7c7.1668045468.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>
---
 drivers/usb/dwc3/gadget.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Greg KH April 13, 2024, 6:02 a.m. UTC | #1 
On Fri, Apr 12, 2024 at 10:26:06PM +0200, A. Sverdlin wrote:
> From: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
> 
> Upstream Linux commit 3aa07f72894d.
> 
> If there's a disconnection while operating in eSS, there may be a delay
> in VBUS drop response from the connector. In that case, the internal
> link state may drop to operate in usb2 speed while the controller thinks
> the VBUS is still high. The driver must make sure to disable
> GUSB2PHYCFG.SUSPHY when sending endpoint command while in usb2 speed.
> The End Transfer command may be called, and only that command needs to
> go through at this point. Let's keep it simple and unconditionally
> disable GUSB2PHYCFG.SUSPHY whenever we issue the command.
> 
> This scenario is not seen in real hardware. In a rare case, our
> prototype type-c controller/interface may have a slow response
> triggerring this issue.
> 
> Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
> Link: https://lore.kernel.org/r/5651117207803c26e2f22ddf4e5ce9e865dcf7c7.1668045468.git.Thinh.Nguyen@synopsys.com
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com>

Confused, why did you resend this to us?
diff mbox series

Patch

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index c14d7870b9461..debfd4d6781db 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -316,7 +316,8 @@  int dwc3_send_gadget_ep_cmd(struct dwc3 *dwc, unsigned ep,
 	 *
 	 * DWC_usb3 3.30a and DWC_usb31 1.90a programming guide section 3.2.2
 	 */
-	if (dwc->gadget.speed <= USB_SPEED_HIGH) {
+	if (dwc->gadget.speed <= USB_SPEED_HIGH ||
+	    DWC3_DEPCMD_CMD(cmd) == DWC3_DEPCMD_ENDTRANSFER) {
 		reg = dwc3_readl(dwc->regs, DWC3_GUSB2PHYCFG(0));
 		if (unlikely(reg & DWC3_GUSB2PHYCFG_SUSPHY)) {
 			saved_config |= DWC3_GUSB2PHYCFG_SUSPHY;