Without this condition, all controllers will do this delay,
and increase the resume time.
Only enabled and unsuspended port needs this delay, but
Some buggy hardware(like Synopsys usb controller) will
clear suspend bit once they receive/send resume signal,
so it takes resume bit as consideration.
Tested it at Freescale i.mx6q Sabrelite board.
Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx>
Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
---
Changes for v3:
- Fix "This continuation line should be indented by one more tab stop"
coding style problem
Changes for v2:
- Fix some coding style problem
- Change ehci_warn to ehci_dbg
drivers/usb/host/ehci-hub.c | 23 ++++++++++++++++++-----
1 files changed, 18 insertions(+), 5 deletions(-)
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 914ce93..a7ec827 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -384,11 +384,24 @@ static int ehci_bus_resume (struct usb_hcd *hcd)
ehci_writel(ehci, ehci->command, &ehci->regs->command);
ehci->rh_state = EHCI_RH_RUNNING;
- /* Some controller/firmware combinations need a delay during which
- * they set up the port statuses. See Bugzilla #8190. */
- spin_unlock_irq(&ehci->lock);
- msleep(8);
- spin_lock_irq(&ehci->lock);
+ /*
+ * According to Bugzilla #8190, the port status for some controllers
+ * will be wrong without a delay. At their wrong status, the port
+ * is enabled, but not suspended neither resumed.
+ */
+ i = HCS_N_PORTS(ehci->hcs_params);
+ while (i--) {
+ temp = ehci_readl(ehci, &ehci->regs->port_status[i]);
+ if ((temp & PORT_PE) &&
+ !(temp & (PORT_SUSPEND | PORT_RESUME))) {
+ ehci_dbg(ehci, "Port status(0x%x) is wrong\n", temp);
+ spin_unlock_irq(&ehci->lock);
+ msleep(8);
+ spin_lock_irq(&ehci->lock);
+ break;
+ }
+ }
+
if (ehci->shutdown)
goto shutdown;
--
1.7.0.4
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