usb: dwc2: make the scheduler handle excessive NAKs better
I'm seeing problems with a d-link dwcl-g122 wifi dongle that
someone sent me. There are reports of other wifi dongles with the
same/similar problem. The devices appear to be NAKing to the point
of confusing the dwc2 driver completely.
The attached patch helps with my d-link dwl-g122 - it's adapted
from the Raspberry Pi dwc_otg driver, which is a modified version
of the Synopsys vendor driver. The error recovery is still valid
after the patch, I think.
Cc: Dom Cobley <popcornmix@gmail.com>
Signed-off-by: Nick Hudson <skrll@netbsd.org>
Signed-off-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/dwc2/hcd_intr.c b/drivers/usb/dwc2/hcd_intr.c
index 47b9eb5..f06249c 100644
--- a/drivers/usb/dwc2/hcd_intr.c
+++ b/drivers/usb/dwc2/hcd_intr.c
@@ -1890,12 +1890,20 @@
"hcint 0x%08x, intsts 0x%08x\n",
chan->hcint,
readl(hsotg->regs + GINTSTS));
+ goto error;
}
}
} else {
dev_info(hsotg->dev,
"NYET/NAK/ACK/other in non-error case, 0x%08x\n",
chan->hcint);
+error:
+ /* Failthrough: use 3-strikes rule */
+ qtd->error_count++;
+ dwc2_update_urb_state_abn(hsotg, chan, chnum, qtd->urb,
+ qtd, DWC2_HC_XFER_XACT_ERR);
+ dwc2_hcd_save_data_toggle(hsotg, chan, chnum, qtd);
+ dwc2_halt_channel(hsotg, chan, qtd, DWC2_HC_XFER_XACT_ERR);
}
}