USB: msm72k_udc: Add counter to reduce delay required for qTD status update
HSUSB PHY is taking time to update the dTD status(INFO_ACTIVE) of the
queued request. So this is checked after a 10us delay, as a data stall
issue is seen without this delay.
Time to get dTD status updated is not deterministic and adding 10us delay
is reducing FTP download throughput. Hence check the status of dTD every
1us for 10 times instead of waiting for 10us.
CRs-Fixed: 371338
Change-Id: Ied0a0792b38a11835df058a187e8974a7cd6671b
Signed-off-by: Rajkumar Raghupathy <raghup@codeaurora.org>
diff --git a/drivers/usb/gadget/msm72k_udc.c b/drivers/usb/gadget/msm72k_udc.c
index a025d95..3e40552 100644
--- a/drivers/usb/gadget/msm72k_udc.c
+++ b/drivers/usb/gadget/msm72k_udc.c
@@ -119,6 +119,7 @@
unsigned long dTD_update_fail_count;
unsigned long false_prime_fail_count;
unsigned actual_prime_fail_count;
+ unsigned long dTD_workaround_fail_count;
unsigned wedged:1;
/* pointers to DMA transfer list area */
@@ -199,6 +200,7 @@
unsigned phy_fail_count;
unsigned prime_fail_count;
unsigned long dTD_update_fail_count;
+ unsigned long dTD_workaround_fail_count;
struct usb_gadget gadget;
struct usb_gadget_driver *driver;
@@ -1110,6 +1112,8 @@
struct msm_request *req;
unsigned long flags;
int req_dequeue = 1;
+ int dtd_update_fail_count_chk = 10;
+ int check_bit = 0;
unsigned info;
/*
@@ -1136,12 +1140,22 @@
/* if the transaction is still in-flight, stop here */
if (info & INFO_ACTIVE) {
if (req_dequeue) {
- req_dequeue = 0;
ui->dTD_update_fail_count++;
ept->dTD_update_fail_count++;
- udelay(10);
+ udelay(1);
+ if (!dtd_update_fail_count_chk--) {
+ req_dequeue = 0;
+ check_bit = 1;
+ }
goto dequeue;
} else {
+ if (check_bit) {
+ pr_debug("%s: Delay Workaround Failed\n",
+ __func__);
+ check_bit = 0;
+ ui->dTD_workaround_fail_count++;
+ ept->dTD_workaround_fail_count++;
+ }
break;
}
}
@@ -1965,11 +1979,14 @@
continue;
i += scnprintf(buf + i, PAGE_SIZE - i,
- "ept%d %s false_prime_count=%lu prime_fail_count=%d dtd_fail_count=%lu\n",
+ "ept%d %s false_prime_count=%lu prime_fail_count=%d "
+ "dtd_fail_count=%lu "
+ "dTD_workaround_fail_count=%lu\n",
ept->num, (ept->flags & EPT_FLAG_IN) ? "in " : "out",
ept->false_prime_fail_count,
ept->actual_prime_fail_count,
- ept->dTD_update_fail_count);
+ ept->dTD_update_fail_count,
+ ept->dTD_workaround_fail_count);
}
i += scnprintf(buf + i, PAGE_SIZE - i,
@@ -1979,6 +1996,10 @@
i += scnprintf(buf + i, PAGE_SIZE - i,
"prime_fail count: %d\n", ui->prime_fail_count);
+ i += scnprintf(buf + i, PAGE_SIZE - i,
+ "dtd_workaround_fail count: %lu\n",
+ ui->dTD_workaround_fail_count);
+
spin_unlock_irqrestore(&ui->lock, flags);
return simple_read_from_buffer(ubuf, count, ppos, buf, i);