Hello.
Mike Frysinger wrote:
From: Bryan Wu <cooloney@xxxxxxxxxx>
Some USB stick does not answer PING correctly which will make USB enumeration fail.
We enable the NAK limit value to detect this PING issue, then disable the PING option
for such ill-behaviored usb sticks.
You're effectively only doing this during the sattus stage. Is that enough?
Signed-off-by: Bryan Wu <cooloney@xxxxxxxxxx>
Signed-off-by: Mike Frysinger <vapier@xxxxxxxxxx>
diff --git a/drivers/usb/musb/musb_core.c b/drivers/usb/musb/musb_core.c
index 4000cf6..6f0b471 100644
--- a/drivers/usb/musb/musb_core.c
+++ b/drivers/usb/musb/musb_core.c
@@ -571,6 +571,7 @@ static irqreturn_t musb_stage0_irq(struct musb *musb, u8 int_usb,
handled = IRQ_HANDLED;
musb->is_active = 1;
set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
+ musb->disable_ping = 0;
musb->ep0_stage = MUSB_EP0_START;
diff --git a/drivers/usb/musb/musb_core.h b/drivers/usb/musb/musb_core.h
index efb39b5..db013dd 100644
--- a/drivers/usb/musb/musb_core.h
+++ b/drivers/usb/musb/musb_core.h
@@ -386,6 +386,9 @@ struct musb {
unsigned is_multipoint:1;
unsigned ignore_disconnect:1; /* during bus resets */
+ /* Disable PING packet to cope with ill-behaved usb thumb drives. */
+ unsigned disable_ping:1;
+
#ifdef C_MP_TX
unsigned bulk_split:1;
#define can_bulk_split(musb,type) \
diff --git a/drivers/usb/musb/musb_host.c b/drivers/usb/musb/musb_host.c
index db1b574..a0b3423 100644
--- a/drivers/usb/musb/musb_host.c
+++ b/drivers/usb/musb/musb_host.c
@@ -1026,6 +1026,11 @@ irqreturn_t musb_h_ep0_irq(struct musb *musb)
} else if (csr & MUSB_CSR0_H_NAKTIMEOUT) {
DBG(2, "control NAK timeout\n");
+ /* For some ill-behaved USB stick, control transfer should
+ * disable PING packet
+ */
+ musb->disable_ping = 1;
+
/* NOTE: this code path would be a good place to PAUSE a
* control transfer, if another one is queued, so that
* ep0 is more likely to stay busy. That's already done
@@ -1085,6 +1090,8 @@ irqreturn_t musb_h_ep0_irq(struct musb *musb)
else
csr = MUSB_CSR0_H_STATUSPKT
| MUSB_CSR0_TXPKTRDY;
+ if (musb->disable_ping)
+ csr |= MUSB_CSR0_H_DIS_PING;
This fails to set the DIS PING bit set if musb_h_ep_continus() returns
non-zero above, i.e. during the data transfers.
WBR, Sergei
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