qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] [PATCH] ehci: clear suspend bit on detach


From: Hans de Goede
Subject: Re: [Qemu-devel] [PATCH] ehci: clear suspend bit on detach
Date: Wed, 21 Oct 2015 09:47:56 +0200
User-agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.3.0

Hi,

On 21-10-15 09:44, Gerd Hoffmann wrote:
When a device is detached, clear the suspend bit (PORTSC_SUSPEND)
in the port status register.

The specs are not *that* clear what is supposed to happen in case
a suspended device is unplugged.  But the enable bit (PORTSC_PED)
is cleared, and the specs mention setting suspend with enable being
unset is undefined behavior.  So clearing them both looks reasonable,
and it actually fixes the reported bug.

https://bugzilla.redhat.com/show_bug.cgi?id=1268879

Cc: Hans de Goede <address@hidden>
Signed-off-by: Gerd Hoffmann <address@hidden>

Thanks for fixing this. Patch looks good to me:

Reviewed-by: Hans de Goede <address@hidden>

Regards,

Hans


---
  hw/usb/hcd-ehci.c | 2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c
index 64a54c6..4e2161b 100644
--- a/hw/usb/hcd-ehci.c
+++ b/hw/usb/hcd-ehci.c
@@ -726,7 +726,7 @@ static void ehci_detach(USBPort *port)
      ehci_queues_rip_device(s, port->dev, 0);
      ehci_queues_rip_device(s, port->dev, 1);

-    *portsc &= ~(PORTSC_CONNECT|PORTSC_PED);
+    *portsc &= ~(PORTSC_CONNECT|PORTSC_PED|PORTSC_SUSPEND);
      *portsc |= PORTSC_CSC;

      ehci_raise_irq(s, USBSTS_PCD);




reply via email to

[Prev in Thread] Current Thread [Next in Thread]