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[Qemu-devel] [PATCH 15/26] uhci: Limit amount of frames processed in one
From: |
Hans de Goede |
Subject: |
[Qemu-devel] [PATCH 15/26] uhci: Limit amount of frames processed in one go |
Date: |
Fri, 14 Dec 2012 14:35:36 +0100 |
Before this patch uhci would process an unlimited amount of frames when
behind on schedule, by setting the timer to a time already past, causing the
timer subsys to immediately recall the frame_timer function gain.
This would cause invalid cancellations of bulk queues when the catching up
processed more then 32 frames at a moment when the bulk qh was temporarily
unlinked (which the Linux uhci driver does).
This patch fixes this by processing maximum 16 frames in one go, and always
setting the timer one ms later, making the code behave more like the ehci
code.
Signed-off-by: Hans de Goede <address@hidden>
---
hw/usb/hcd-uhci.c | 43 +++++++++++++++++++++++++++----------------
1 file changed, 27 insertions(+), 16 deletions(-)
diff --git a/hw/usb/hcd-uhci.c b/hw/usb/hcd-uhci.c
index 11ccdc8..2a5d4cc 100644
--- a/hw/usb/hcd-uhci.c
+++ b/hw/usb/hcd-uhci.c
@@ -78,6 +78,8 @@
/* Must be large enough to handle 10 frame delay for initial isoc requests */
#define QH_VALID 32
+#define MAX_FRAMES_PER_TICK (QH_VALID / 2)
+
#define NB_PORTS 2
enum {
@@ -500,7 +502,7 @@ static void uhci_ioport_writew(void *opaque, uint32_t addr,
uint32_t val)
trace_usb_uhci_schedule_start();
s->expire_time = qemu_get_clock_ns(vm_clock) +
(get_ticks_per_sec() / FRAME_TIMER_FREQ);
- qemu_mod_timer(s->frame_timer, qemu_get_clock_ns(vm_clock));
+ qemu_mod_timer(s->frame_timer, s->expire_time);
s->status &= ~UHCI_STS_HCHALTED;
} else if (!(val & UHCI_CMD_RS)) {
s->status |= UHCI_STS_HCHALTED;
@@ -1176,10 +1178,10 @@ static void uhci_bh(void *opaque)
static void uhci_frame_timer(void *opaque)
{
UHCIState *s = opaque;
+ uint64_t t_now, t_last_run;
+ int i, frames;
+ const uint64_t frame_t = get_ticks_per_sec() / FRAME_TIMER_FREQ;
- /* prepare the timer for the next frame */
- s->expire_time += (get_ticks_per_sec() / FRAME_TIMER_FREQ);
- s->frame_bytes = 0;
s->completions_only = false;
qemu_bh_cancel(s->bh);
@@ -1193,20 +1195,29 @@ static void uhci_frame_timer(void *opaque)
return;
}
- /* Process the current frame */
- trace_usb_uhci_frame_start(s->frnum);
-
- uhci_async_validate_begin(s);
-
- uhci_process_frame(s);
+ /* We still store expire_time in our state, for migration */
+ t_last_run = s->expire_time - frame_t;
+ t_now = qemu_get_clock_ns(vm_clock);
- uhci_async_validate_end(s);
+ /* Process up to MAX_FRAMES_PER_TICK frames */
+ frames = (t_now - t_last_run) / frame_t;
+ if (frames > MAX_FRAMES_PER_TICK) {
+ frames = MAX_FRAMES_PER_TICK;
+ }
- /* The uhci spec says frnum reflects the frame currently being processed,
- * and the guest must look at frnum - 1 on interrupt, so inc frnum now */
- s->frnum = (s->frnum + 1) & 0x7ff;
+ for (i = 0; i < frames; i++) {
+ s->frame_bytes = 0;
+ trace_usb_uhci_frame_start(s->frnum);
+ uhci_async_validate_begin(s);
+ uhci_process_frame(s);
+ uhci_async_validate_end(s);
+ /* The spec says frnum is the frame currently being processed, and
+ * the guest must look at frnum - 1 on interrupt, so inc frnum now */
+ s->frnum = (s->frnum + 1) & 0x7ff;
+ s->expire_time += frame_t;
+ }
- /* Complete the previous frame */
+ /* Complete the previous frame(s) */
if (s->pending_int_mask) {
s->status2 |= s->pending_int_mask;
s->status |= UHCI_STS_USBINT;
@@ -1214,7 +1225,7 @@ static void uhci_frame_timer(void *opaque)
}
s->pending_int_mask = 0;
- qemu_mod_timer(s->frame_timer, s->expire_time);
+ qemu_mod_timer(s->frame_timer, t_now + frame_t);
}
static const MemoryRegionPortio uhci_portio[] = {
--
1.8.0.1
- Re: [Qemu-devel] [PATCH 09/26] ehci: Use uframe precision for interrupt threshold checking, (continued)
[Qemu-devel] [PATCH 12/26] uhci: Fix 1 ms delay in interrupt reporting to the guest, Hans de Goede, 2012/12/14
[Qemu-devel] [PATCH 10/26] ehci: Further speedup rescanning if async schedule after raising an interrupt, Hans de Goede, 2012/12/14
[Qemu-devel] [PATCH 11/26] ehci: Don't call commit_irq after raising PCD, Hans de Goede, 2012/12/14
[Qemu-devel] [PATCH 13/26] uhci: Fix pending interrupts getting lost on migration, Hans de Goede, 2012/12/14
[Qemu-devel] [PATCH 14/26] uhci: Add a QH_VALID define, Hans de Goede, 2012/12/14
[Qemu-devel] [PATCH 17/26] hid: Change idle handling to use a timer, Hans de Goede, 2012/12/14
[Qemu-devel] [PATCH 15/26] uhci: Limit amount of frames processed in one go,
Hans de Goede <=
[Qemu-devel] [PATCH 20/26] usbredir: Add an usbredir_stop_ep helper function, Hans de Goede, 2012/12/14
[Qemu-devel] [PATCH 19/26] usb: Add an usb_device_ep_stopped USBDevice method, Hans de Goede, 2012/12/14
[Qemu-devel] [PATCH 16/26] uhci: Maximize how many frames we catch up when behind, Hans de Goede, 2012/12/14
[Qemu-devel] [PATCH 21/26] usbredir: Add USBEP2I and I2USBEP helper macros, Hans de Goede, 2012/12/14
[Qemu-devel] [PATCH 22/26] usbredir: Add ep_stopped USBDevice method, Hans de Goede, 2012/12/14
[Qemu-devel] [PATCH 23/26] usbredir: Verify we have 32 bits bulk length cap when redirecting to xhci, Hans de Goede, 2012/12/14
[Qemu-devel] [PATCH 26/26] usbredir: Add support for buffered bulk input, Hans de Goede, 2012/12/14