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[Qemu-devel] [PATCH 08/36] ehci: Retry to fill the queue while waiting f
From: |
Gerd Hoffmann |
Subject: |
[Qemu-devel] [PATCH 08/36] ehci: Retry to fill the queue while waiting for td completion |
Date: |
Thu, 25 Oct 2012 14:51:41 +0200 |
From: Hans de Goede <address@hidden>
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 <address@hidden>
Signed-off-by: Gerd Hoffmann <address@hidden>
---
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
- [Qemu-devel] [PULL 00/36] usb patch queue, Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 02/36] uhci: Move checks to continue queuing to uhci_fill_queue(), Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 20/36] uhci: Move emptying of the queue's asyncs' queue to uhci_queue_free, Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 33/36] xhci: flush endpoint context unconditinally, Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 10/36] usb: Rename __usb_packet_complete to usb_packet_complete_one, Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 03/36] ehci: Get rid of packet tbytes field, Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 29/36] uhci: Always mark a queue valid when we encounter it, Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 18/36] uhci: Don't retry on error, Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 11/36] usb: Add USB_RET_ADD_TO_QUEUE packet result code, Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 08/36] ehci: Retry to fill the queue while waiting for td completion,
Gerd Hoffmann <=
- [Qemu-devel] [PATCH 15/36] usb: Enforce iso endpoints never returing USB_RET_ASYNC, Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 01/36] uhci: Properly unmap packets on cancel / invalid pid, Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 06/36] ehci: Speed up the timer of raising int from the async schedule, Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 32/36] xhci: fix function name in error message, Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 12/36] usb: Move clearing of queue on halt to the core, Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 16/36] uhci: No need to handle async completion of isoc packets, Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 34/36] xhci: allow disabling interrupters, Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 21/36] uhci: Rename UHCIAsync->td to UHCIAsync->td_addr, Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 28/36] uhci: When the guest marks a pending td non-active, cancel the queue, Gerd Hoffmann, 2012/10/25
- [Qemu-devel] [PATCH 27/36] uhci: Detect guest td re-use, Gerd Hoffmann, 2012/10/25