On 18 April 2011 20:51, Matej Kenda <matejken@xxxxxxxxx> wrote:
> On 18 April 2011 17:28, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
>>>
>>> A bug report 701011 in Launchpad contains additional description of
>>> the problem and kernel logs with traces created with
>>> options:
>>>
>>> CONFIG_USB_STORAGE_DEBUG=y
>>> CONFIG_USB=y
>>> CONFIG_USB_DEBUG=y
>>>
>>> https://bugs.launchpad.net/linux/+bug/701011
>>> https://launchpadlibrarian.net/62011653/hudson-slave-last-part.log
>>
>> Here's a patch for you to test. ÂIt isn't exactly a reversion of the
>> "USB: ehci-hcd unlink speedups" commit.
>
> Thank you. I'll try the patch.
It took me some time to set up the test environment with patched
kernel. There was some other work that I needed to complete. I had to
upgrade my LKM for custom piece of hardware to be able to run the
test.
I applied the patch to Linux kernel from Ubuntu Natty (2.6.38-10). I
needed to modify the patch slightly.
I will report how it works in a week or so.
Regards,
Matej
diff --git a/debian.master/changelog b/debian.master/changelog
index 7936595..9d4cb21 100644
--- a/debian.master/changelog
+++ b/debian.master/changelog
@@ -1,3 +1,10 @@
+linux (2.6.38-10.99) natty; urgency=low
+
+ * USB disconnect: Test patch from Alan Stern
+ - LP: #701011
+
+ -- Matej Kenda <matej.kenda@xxxxxxxxx> Tue, 19 Apr 2011 13:16:59 +0200
+
linux (2.6.38-9.43) natty-proposed; urgency=low
[ Brad Figg ]
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 74dcf49..bbce753 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -90,7 +90,7 @@ static const char hcd_name [] = "ehci_hcd";
#define EHCI_IAA_MSECS 10 /* arbitrary */
#define EHCI_IO_JIFFIES (HZ/10) /* io watchdog > irq_thresh */
#define EHCI_ASYNC_JIFFIES (HZ/20) /* async idle timeout */
-#define EHCI_SHRINK_FRAMES 5 /* async qh unlink delay */
+#define EHCI_SHRINK_JIFFIES (HZ/200 + 2) /* async qh unlink delay */
/* Initial IRQ latency: faster than hw default */
static int log2_irq_thresh = 0; // 0 to 6
@@ -150,10 +150,7 @@ timer_action(struct ehci_hcd *ehci, enum ehci_timer_action action)
break;
/* case TIMER_ASYNC_SHRINK: */
default:
- /* add a jiffie since we synch against the
- * 8 KHz uframe counter.
- */
- t = DIV_ROUND_UP(EHCI_SHRINK_FRAMES * HZ, 1000) + 1;
+ t = EHCI_SHRINK_JIFFIES;
break;
}
mod_timer(&ehci->watchdog, t + jiffies);
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index baf7362..35e8957 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -1249,7 +1249,8 @@ static void scan_async (struct ehci_hcd *ehci)
struct ehci_qh *qh;
enum ehci_timer_action action = TIMER_IO_WATCHDOG;
- ehci->stamp = ehci_readl(ehci, &ehci->regs->frame_index);
+ ehci->stamp++;
+ ehci->stamp += !ehci->stamp;
timer_action_done (ehci, TIMER_ASYNC_SHRINK);
rescan:
stopped = !HC_IS_RUNNING(ehci_to_hcd(ehci)->state);
@@ -1272,6 +1273,7 @@ rescan:
temp = qh_completions (ehci, qh);
if (qh->needs_rescan)
unlink_async(ehci, qh);
+ qh->unlink_time = jiffies + EHCI_SHRINK_JIFFIES;
qh_put (qh);
if (temp != 0) {
goto rescan;
@@ -1286,9 +1288,8 @@ rescan:
*/
if (list_empty(&qh->qtd_list)
&& qh->qh_state == QH_STATE_LINKED) {
- if (!ehci->reclaim && (stopped ||
- ((ehci->stamp - qh->stamp) & 0x1fff)
- >= EHCI_SHRINK_FRAMES * 8))
+ if (!ehci->reclaim && (stopped ||
+ time_after_eq(jiffies, qh->unlink_time)))
start_unlink_async(ehci, qh);
else
action = TIMER_ASYNC_SHRINK;
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 799ac16..8fd4cc9 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -336,6 +336,8 @@ struct ehci_qh {
struct ehci_qh *reclaim; /* next to reclaim */
struct ehci_hcd *ehci;
+ unsigned long unlink_time;
+ unsigned stamp;
/*
* Do NOT use atomic operations for QH refcounting. On some CPUs
@@ -344,7 +346,6 @@ struct ehci_qh {
* Spinlocks are used to protect all QH fields.
*/
u32 refcount;
- unsigned stamp;
u8 needs_rescan; /* Dequeue during giveback */
u8 qh_state;
