[Qemu-devel] [PATCH 0/2] ehci: Misc fixes

[Qemu-devel] [PATCH 0/2] ehci: Misc fixes

[Hans de Goede]

Here is a better version of the "ehci: Don't process too much frames in 1
timer tick" patch, replacing the one from my last pull-req, as well as a
small bugfix for an issue I noticed while working on this.

Thanks & Regards,

Hans

[Qemu-devel] [PATCH 1/2] ehci: Fix interrupts stopping when Interrupt Threshold Control is 8

[Hans de Goede]

If Interrupt Threshold Control is 8 or a multiple of 8, then
s->usbsts_frindex can become exactly 0x4000, at which point
(s->usbsts_frindex > s->frindex) will never become true, as
s->usbsts_frindex will not be lowered / reset in this case.

This patch fixes this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 hw/usb/hcd-ehci.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c
index 30d2b56..e6d2062 100644
--- a/hw/usb/hcd-ehci.c
+++ b/hw/usb/hcd-ehci.c
@@ -2426,7 +2426,7 @@ static void ehci_update_frindex(EHCIState *ehci, int frames)
         if (ehci->frindex == 0x00004000) {
             ehci_raise_irq(ehci, USBSTS_FLR);
             ehci->frindex = 0;
-            if (ehci->usbsts_frindex > 0x00004000) {
+            if (ehci->usbsts_frindex >= 0x00004000) {
                 ehci->usbsts_frindex -= 0x00004000;
             } else {
                 ehci->usbsts_frindex = 0;
-- 
1.7.12

[Qemu-devel] [PATCH 2/2] ehci: Don't process too much frames in 1 timer tick (v2)

[Hans de Goede]

The Linux ehci isoc scheduling code fills the entire schedule ahead of
time minus 80 frames. If we make a large jump in where we are in the
schedule, ie 40 frames, then the scheduler all of a sudden will only have
40 frames left to work in, causing it to fail packet submissions
with error -27 (-EFBIG).

Changes in v2:
-Don't hardcode a maximum number of frames to process in one tick, instead:
 -Process a minimum number of frames to ensure we do eventually catch up
 -Stop (after the minimum number) when the guest has requested an irq

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 hw/usb/hcd-ehci.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c
index e6d2062..48a1b09 100644
--- a/hw/usb/hcd-ehci.c
+++ b/hw/usb/hcd-ehci.c
@@ -140,6 +140,7 @@
 #define NB_PORTS         6        // Number of downstream ports
 #define BUFF_SIZE        5*4096   // Max bytes to transfer per transaction
 #define MAX_QH           100      // Max allowable queue heads in a chain
+#define MIN_FR_PER_TICK  3        // Min frames to process when catching up
 
 /*  Internal periodic / asynchronous schedule state machine states
  */
@@ -2461,6 +2462,19 @@ static void ehci_frame_timer(void *opaque)
         }
 
         for (i = 0; i < frames; i++) {
+            /* 
+             * If we're running behind schedule, we should not catch up
+             * too fast, as that will make some guests unhappy:
+             * 1) We must process a minimum of MIN_FR_PER_TICK frames,
+             *    otherwise we will never catch up
+             * 2) Process frames until the guest has requested an irq (IOC)
+             */
+            if (i >= MIN_FR_PER_TICK) {
+                ehci_commit_irq(ehci);
+                if ((ehci->usbsts & USBINTR_MASK) & ehci->usbintr) {
+                    break;
+                }
+            }
             ehci_update_frindex(ehci, 1);
             ehci_advance_periodic_state(ehci);
             ehci->last_run_ns += FRAME_TIMER_NS;
-- 
1.7.12

Re: [Qemu-devel] [PATCH 0/2] ehci: Misc fixes

[Gerd Hoffmann]

On 09/10/12 12:44, Hans de Goede wrote:
> Here is a better version of the "ehci: Don't process too much frames in 1
> timer tick" patch, replacing the one from my last pull-req, as well as a
> small bugfix for an issue I noticed while working on this.
> 
> Thanks & Regards,
> 
> Hans

Patches added to usb patch queue.

thanks,
  Gerd

Re: [Qemu-devel] [PATCH 0/2] ehci: Misc fixes

[Hans de Goede]

Hi,

On 09/10/2012 03:34 PM, Gerd Hoffmann wrote:
> On 09/10/12 12:44, Hans de Goede wrote:
>> Here is a better version of the "ehci: Don't process too much frames in 1
>> timer tick" patch, replacing the one from my last pull-req, as well as a
>> small bugfix for an issue I noticed while working on this.
>>
>> Thanks & Regards,
>>
>> Hans
>
> Patches added to usb patch queue.

Thanks, but it seems you missed the ones from my pull-req, from
a few days ago, iow those queued up here:

http://cgit.freedesktop.org/~jwrdegoede/qemu/log/?h=usb-for-gerd

Except for the "ehci: Don't process too much frames in 1 timer tick"
patch as you've already added v2 of that :)

If you want I can re-spin and send them as patches to the list.

Regards,

Hans

Re: [Qemu-devel] [PATCH 0/2] ehci: Misc fixes

[Gerd Hoffmann]

  Hi,

> http://cgit.freedesktop.org/~jwrdegoede/qemu/log/?h=usb-for-gerd
> 
> Except for the "ehci: Don't process too much frames in 1 timer tick"
> patch as you've already added v2 of that :)
> 
> If you want I can re-spin and send them as patches to the list.

Phew, usb backlog is merged.  Can you respin (against master should work
now) and send to the list?

thanks,
  Gerd