FAILED: patch "[PATCH] usb: musb: da8xx: fix babble condition handling" failed to apply to 4.14-stable tree

The patch below does not apply to the 4.14-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From: Bin Liu <[email protected]>
Date: Tue, 5 Dec 2017 08:45:30 -0600
Subject: [PATCH] usb: musb: da8xx: fix babble condition handling

When babble condition happens, the musb controller might automatically turns off VBUS. On DA8xx platform, the controller generates drvvbus interrupt for turning off VBUS along with the babble interrupt.

In this case, we should handle the babble interrupt first and recover from the babble condition.

This change ignores the drvvbus interrupt if babble interrupt is also generated at the same time, so the babble recovery routine works properly.

index 0397606a211b..6c036de63272 100644
@@ -284,7 +284,15 @@ static irqreturn_t da8xx_musb_interrupt(int irq, void *hci)
 			musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
 			portstate(musb->port1_status |= USB_PORT_STAT_POWER);
 			del_timer(&musb->dev_timer);
-		} else {
+		} else if (!(musb->int_usb & MUSB_INTR_BABBLE)) {
+			/*
+			 * When babble condition happens, drvvbus interrupt
+			 * is also generated. Ignore this drvvbus interrupt
+			 * and let babble interrupt handler recovers the
+			 * controller; otherwise, the host-mode flag is lost
+			 * due to the MUSB_DEV_MODE() call below and babble
+			 * recovery logic will not be called.
+			 */
 			musb->is_active = 0;
 			MUSB_DEV_MODE(musb);
 			otg->default_a = 0;

When babble condition happens, the musb controller might automatically turns off VBUS. On DA8xx platform, the controller generates drvvbus interrupt for turning off VBUS along with the babble interrupt.

In this case, we should handle the babble interrupt first and recover from the babble condition.

This change ignores the drvvbus interrupt if babble interrupt is also generated, so the babble recovery routine works properly.

c: [email protected] # v3.16+

---
 drivers/usb/musb/da8xx.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

index 0032441d68dd..ca8151f667c6 100644
@@ -306,7 +306,15 @@ static irqreturn_t da8xx_musb_interrupt(int irq, void *hci)
 			musb->xceiv->otg->state = OTG_STATE_A_WAIT_VRISE;
 			portstate(musb->port1_status |= USB_PORT_STAT_POWER);
 			del_timer(&otg_workaround);
-		} else {
+		} else if (!(musb->int_usb & MUSB_INTR_BABBLE)){
+			/*
+			 * When babble condition happens, drvvbus interrupt
+			 * is also generated. Ignore this drvvbus interrupt
+			 * and let babble interrupt handler recovers the
+			 * controller; otherwise, the host-mode flag is lost
+			 * due to the MUSB_DEV_MODE() call below and babble
+			 * recovery logic will not called.
+			 */
 			musb->is_active = 0;
 			MUSB_DEV_MODE(musb);
 			otg->default_a = 0;

1.9.1

Next time, please give me a hint that this was commit bd3486ded7a0c313a6575343e6c2b21d14476645 in Linus's tree so I don't have to dig it out :)

thanks,

greg k-h

I am sorry. I should have checked the format of backport patches first.

Regards,
-Bin.