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[Qemu-devel] [PATCH 08/22] ehci: Retry to fill the queue while waiting f
From: |
Hans de Goede |
Subject: |
[Qemu-devel] [PATCH 08/22] ehci: Retry to fill the queue while waiting for td completion |
Date: |
Wed, 24 Oct 2012 18:14:04 +0200 |
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>
---
hw/usb/hcd-ehci.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c
index c906ab8..ad52850 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)
{
@@ -1993,7 +1994,7 @@ 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);
@@ -2021,7 +2022,6 @@ 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:
@@ -2030,6 +2030,9 @@ 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;
@@ -2041,13 +2044,11 @@ 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;
--
1.7.12.1
- [Qemu-devel] usb: input-pipelining + speedups v3, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 02/22] uhci: Move checks to continue queuing to uhci_fill_queue(), Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 01/22] uhci: Properly unmap packets on cancel / invalid pid, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 06/22] ehci: Speed up the timer of raising int from the async schedule, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 05/22] ehci: Improve latency of interrupt delivery and async schedule scanning, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 03/22] ehci: Get rid of packet tbytes field, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 10/22] usb: Rename __usb_packet_complete to usb_packet_complete_one, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 07/22] ehci: Detect going in circles when filling the queue, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 04/22] ehci: Set int flag on a short input packet, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 11/22] usb: Add USB_RET_ADD_TO_QUEUE packet result code, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 08/22] ehci: Retry to fill the queue while waiting for td completion,
Hans de Goede <=
- [Qemu-devel] [PATCH 09/22] xhci: Add a xhci_ep_nuke_one_xfer helper function, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 16/22] combined-packet: Add a workaround for Linux usbfs + live migration, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 12/22] usb: Move clearing of queue on halt to the core, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 13/22] usb: Move short-not-ok handling to the core, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 22/22] usb-redir: Allow redirecting super speed devices to high speed controllers, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 17/22] usb-redir: Add support for 32 bits bulk packet length, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 18/22] usb-redir: Add support for input pipelining, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 19/22] usb-redir: Add an usbredir_setup_usb_eps() helper function, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 14/22] usb: Add an int_req flag to USBPacket, Hans de Goede, 2012/10/24
- [Qemu-devel] [PATCH 15/22] usb: Add packet combining functions, Hans de Goede, 2012/10/24