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Blame 0126-usb-ehci-Handle-ISO-packets-failing-with-an-error-ot.patch

Hans de Goede 1b1995
From 7a3acb928b617b33605c779e7df05c2c896844b1 Mon Sep 17 00:00:00 2001
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From: Hans de Goede <hdegoede@redhat.com>
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Date: Mon, 20 Feb 2012 16:27:47 +0100
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Subject: [PATCH 126/140] usb-ehci: Handle ISO packets failing with an error
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 other then NAK
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Before this patch the ehci code was not checking for any other errors other
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then USB_RET_NAK. This causes 2 problems:
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1) Other errors are not reported to the guest.
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2) When transactions with the ITD_XACT_IOC bit set completing with another
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   error would not result in USBSTS_INT getting set.
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I hit this problem when unplugging devices while iso data was streaming from
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the device to the guest. When this happens it takes a while for the guest to
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process the unplugging and remove ISO transactions from the ehci schedule, in
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the mean time these transactions would complete with a result of USB_RET_NODEV,
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which was not handled. This lead to the Linux guest's usb subsystem "hanging",
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that is it would no longer see new usb devices getting plugged in and running
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for example lsusb would lead to a stuck (D state) lsusb process. This patch
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fixes this.
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Signed-off-by: Hans de Goede <hdegoede@redhat.com>
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---
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 hw/usb-ehci.c |   22 +++++++++++++++++++---
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 1 file changed, 19 insertions(+), 3 deletions(-)
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diff --git a/hw/usb-ehci.c b/hw/usb-ehci.c
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index 69bcc4b..a6b6ae5 100644
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--- a/hw/usb-ehci.c
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+++ b/hw/usb-ehci.c
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@@ -1512,11 +1512,27 @@ static int ehci_process_itd(EHCIState *ehci,
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                     /* IN */
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                     set_field(&itd->transact[i], ret, ITD_XACT_LENGTH);
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                 }
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-
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-                if (itd->transact[i] & ITD_XACT_IOC) {
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-                    ehci_record_interrupt(ehci, USBSTS_INT);
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+            } else {
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+                switch (ret) {
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+                default:
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+                    fprintf(stderr, "Unexpected iso usb result: %d\n", ret);
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+                    /* Fall through */
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+                case USB_RET_NODEV:
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+                    /* 3.3.2: XACTERR is only allowed on IN transactions */
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+                    if (dir) {
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+                        itd->transact[i] |= ITD_XACT_XACTERR;
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+                        ehci_record_interrupt(ehci, USBSTS_ERRINT);
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+                    }
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+                    break;
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+                case USB_RET_BABBLE:
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+                    itd->transact[i] |= ITD_XACT_BABBLE;
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+                    ehci_record_interrupt(ehci, USBSTS_ERRINT);
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+                    break;
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                 }
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             }
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+            if (itd->transact[i] & ITD_XACT_IOC) {
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+                ehci_record_interrupt(ehci, USBSTS_INT);
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+            }
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             itd->transact[i] &= ~ITD_XACT_ACTIVE;
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         }
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     }
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-- 
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1.7.9.3
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