From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:59875) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TRMv7-0006oz-Mg for qemu-devel@nongnu.org; Thu, 25 Oct 2012 08:52:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TRMv0-0003AD-5m for qemu-devel@nongnu.org; Thu, 25 Oct 2012 08:52:21 -0400 Received: from mx1.redhat.com ([209.132.183.28]:2652) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TRMuz-00039i-Tr for qemu-devel@nongnu.org; Thu, 25 Oct 2012 08:52:14 -0400 Received: from int-mx12.intmail.prod.int.phx2.redhat.com (int-mx12.intmail.prod.int.phx2.redhat.com [10.5.11.25]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id q9PCqDVF011065 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 25 Oct 2012 08:52:13 -0400 From: Gerd Hoffmann Date: Thu, 25 Oct 2012 14:51:41 +0200 Message-Id: <1351169529-10799-9-git-send-email-kraxel@redhat.com> In-Reply-To: <1351169529-10799-1-git-send-email-kraxel@redhat.com> References: <1351169529-10799-1-git-send-email-kraxel@redhat.com> Subject: [Qemu-devel] [PATCH 08/36] ehci: Retry to fill the queue while waiting for td completion List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Hans de Goede , Gerd Hoffmann From: Hans de Goede If the guest is using multiple transfers to try and keep the usb bus busy / used at maximum efficiency, currently we would see / do the following: 1) submit transfer 1 to the device 2) submit transfer 2 to the device 3) report transfer 1 completion to guest 4) report transfer 2 completion to guest 5) submit transfer 1 to the device 6) report transfer 1 completion to guest 7) submit transfer 2 to the device 8) report transfer 2 completion to guest etc. So after the initial submission we would effectively only have 1 transfer in flight, rather then 2. This is caused by us not checking the queue for addition of new transfers by the guest (ie the resubmission of a recently finished transfer), while waiting for a pending transfer to complete. This patch does add a check for this, changing the sequence to: 1) submit transfer 1 to the device 2) submit transfer 2 to the device 3) report transfer 1 completion to guest 4) submit transfer 1 to the device 5) report transfer 2 completion to guest 6) submit transfer 2 to the device etc. Thus keeping 2 transfers in flight (most of the time, and always 1), as intended by the guest. Signed-off-by: Hans de Goede Signed-off-by: Gerd Hoffmann --- hw/usb/hcd-ehci.c | 11 ++++++----- 1 files changed, 6 insertions(+), 5 deletions(-) diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c index 8bd87c7..a02fe96 100644 --- a/hw/usb/hcd-ehci.c +++ b/hw/usb/hcd-ehci.c @@ -381,7 +381,7 @@ struct EHCIQueue { uint32_t qhaddr; /* address QH read from */ uint32_t qtdaddr; /* address QTD read from */ USBDevice *dev; - QTAILQ_HEAD(, EHCIPacket) packets; + QTAILQ_HEAD(pkts_head, EHCIPacket) packets; }; typedef QTAILQ_HEAD(EHCIQueueHead, EHCIQueue) EHCIQueueHead; @@ -488,6 +488,7 @@ static const char *ehci_mmio_names[] = { static int ehci_state_executing(EHCIQueue *q); static int ehci_state_writeback(EHCIQueue *q); +static int ehci_fill_queue(EHCIPacket *p); static const char *nr2str(const char **n, size_t len, uint32_t nr) { @@ -1994,7 +1995,7 @@ static int ehci_state_fetchqtd(EHCIQueue *q) { EHCIqtd qtd; EHCIPacket *p; - int again = 0; + int again = 1; get_dwords(q->ehci, NLPTR_GET(q->qtdaddr), (uint32_t *) &qtd, sizeof(EHCIqtd) >> 2); @@ -2022,7 +2023,6 @@ static int ehci_state_fetchqtd(EHCIQueue *q) p = NULL; } ehci_set_state(q->ehci, q->async, EST_HORIZONTALQH); - again = 1; } else if (p != NULL) { switch (p->async) { case EHCI_ASYNC_NONE: @@ -2031,6 +2031,9 @@ static int ehci_state_fetchqtd(EHCIQueue *q) ehci_set_state(q->ehci, q->async, EST_EXECUTE); break; case EHCI_ASYNC_INFLIGHT: + /* Check if the guest has added new tds to the queue */ + again = (ehci_fill_queue(QTAILQ_LAST(&q->packets, pkts_head)) == + USB_RET_PROCERR) ? -1 : 1; /* Unfinished async handled packet, go horizontal */ ehci_set_state(q->ehci, q->async, EST_HORIZONTALQH); break; @@ -2042,13 +2045,11 @@ static int ehci_state_fetchqtd(EHCIQueue *q) ehci_set_state(q->ehci, q->async, EST_EXECUTING); break; } - again = 1; } else { p = ehci_alloc_packet(q); p->qtdaddr = q->qtdaddr; p->qtd = qtd; ehci_set_state(q->ehci, q->async, EST_EXECUTE); - again = 1; } return again; -- 1.7.1