From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:38970) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T7nrj-00071o-Mr for qemu-devel@nongnu.org; Sat, 01 Sep 2012 09:36:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T7nre-0005JE-7C for qemu-devel@nongnu.org; Sat, 01 Sep 2012 09:35:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:1379) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T7nrd-0005J8-V2 for qemu-devel@nongnu.org; Sat, 01 Sep 2012 09:35:54 -0400 Message-ID: <50420F7F.5000000@redhat.com> Date: Sat, 01 Sep 2012 15:37:03 +0200 From: Hans de Goede MIME-Version: 1.0 References: <1346422762-15877-1-git-send-email-kraxel@redhat.com> <1346422762-15877-3-git-send-email-kraxel@redhat.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH for-1.2 02/11] usb: Halt ep queue en cancel pending packets on a packet error List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Blue Swirl Cc: Gerd Hoffmann , qemu-devel@nongnu.org Hi, On 09/01/2012 12:42 PM, Blue Swirl wrote: > On Fri, Aug 31, 2012 at 2:19 PM, Gerd Hoffmann wrote: >> From: Hans de Goede >> >> For controllers which queue up more then 1 packet at a time, we must halt the >> ep queue, and inside the controller code cancel all pending packets on an >> error. >> >> There are multiple reasons for this: >> 1) Guests expect the controllers to halt ep queues on error, so that they >> get the opportunity to cancel transfers which the scheduled after the failing >> one, before processing continues >> >> 2) Not cancelling queued up packets after a failed transfer also messes up >> the controller state machine, in the case of EHCI causing the following >> assert to trigger: "assert(p->qtdaddr == q->qtdaddr)" at hcd-ehci.c:2075 >> >> 3) For bulk endpoints with pipelining enabled (redirection to a real USB >> device), we must cancel all the transfers after this a failed one so that: >> a) If they've completed already, they are not processed further causing more >> stalls to be reported, originating from the same failed transfer >> b) If still in flight, they are cancelled before the guest does >> a clear stall, otherwise the guest and device can loose sync! >> >> Note this patch only touches the ehci and uhci controller changes, since AFAIK >> no other controllers actually queue up multiple transfer. If I'm wrong on this >> other controllers need to be updated too! >> >> Also note that this patch was heavily tested with the ehci code, where I had >> a reproducer for a device causing a transfer to fail. The uhci code is not >> tested with actually failing transfers and could do with a thorough review! >> >> Signed-off-by: Hans de Goede >> Signed-off-by: Gerd Hoffmann >> --- >> hw/usb.h | 1 + >> hw/usb/core.c | 35 ++++++++++++++++++++++++++++------- >> hw/usb/hcd-ehci.c | 13 +++++++++++++ >> hw/usb/hcd-uhci.c | 16 ++++++++++++++++ >> 4 files changed, 58 insertions(+), 7 deletions(-) >> >> diff --git a/hw/usb.h b/hw/usb.h >> index 432ccae..e574477 100644 >> --- a/hw/usb.h >> +++ b/hw/usb.h >> @@ -179,6 +179,7 @@ struct USBEndpoint { >> uint8_t ifnum; >> int max_packet_size; >> bool pipeline; >> + bool halted; >> USBDevice *dev; >> QTAILQ_HEAD(, USBPacket) queue; >> }; >> diff --git a/hw/usb/core.c b/hw/usb/core.c >> index c7e5bc0..28b840e 100644 >> --- a/hw/usb/core.c >> +++ b/hw/usb/core.c >> @@ -382,12 +382,23 @@ int usb_handle_packet(USBDevice *dev, USBPacket *p) >> usb_packet_check_state(p, USB_PACKET_SETUP); >> assert(p->ep != NULL); >> >> + /* Submitting a new packet clears halt */ >> + if (p->ep->halted) { >> + assert(QTAILQ_EMPTY(&p->ep->queue)); >> + p->ep->halted = false; >> + } >> + >> if (QTAILQ_EMPTY(&p->ep->queue) || p->ep->pipeline) { >> ret = usb_process_one(p); >> if (ret == USB_RET_ASYNC) { >> usb_packet_set_state(p, USB_PACKET_ASYNC); >> QTAILQ_INSERT_TAIL(&p->ep->queue, p, queue); >> } else { >> + /* >> + * When pipelining is enabled usb-devices must always return async, >> + * otherwise packets can complete out of order! >> + */ >> + assert(!p->ep->pipeline); >> p->result = ret; >> usb_packet_set_state(p, USB_PACKET_COMPLETE); >> } >> @@ -399,6 +410,20 @@ int usb_handle_packet(USBDevice *dev, USBPacket *p) >> return ret; >> } >> >> +static void __usb_packet_complete(USBDevice *dev, USBPacket *p) > > Please check reserved namespaces in HACKING. That talks about suffixes not prefixes. Regards, Hans