From: Sergei Shtylyov <sshtyl...@ru.mvista.com>

MAX4967 USB power supply chip we use on our boards signals over-current when
power is not enabled; once it's enabled, over-current signal returns to normal.
That unfortunately caused the endless stream of "over-current change on port"
messages. The EHCI root hub code reacts on every over-current signal change
with powering off the port -- such change event is generated the moment the
port power is enabled, so once enabled the power is immediately cut off.
I think we should only cut off power when we're seeing the active over-current
signal, so I'm adding such check to that code. I also think that the fact that
we've cut off the port power should be reflected in the result of GetPortStatus
request immediately, hence I'm adding a PORTSCn register readback after write...

Signed-off-by: Sergei Shtylyov <sshtyl...@ru.mvista.com>
Cc: sta...@kernel.org
Acked-by: Alan Stern <st...@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gre...@suse.de>
---
 drivers/usb/host/ehci-hub.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index d9e8d71..bf2c8f6 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -816,10 +816,11 @@ static int ehci_hub_control (
                         * power switching; they're allowed to just limit the
                         * current.  khubd will turn the power back on.
                         */
-                       if (HCS_PPC (ehci->hcs_params)){
+                       if ((temp & PORT_OC) && HCS_PPC(ehci->hcs_params)) {
                                ehci_writel(ehci,
                                        temp & ~(PORT_RWC_BITS | PORT_POWER),
                                        status_reg);
+                               temp = ehci_readl(ehci, status_reg);
                        }
                }
 
-- 
1.7.6

_______________________________________________
stable mailing list
stable@linux.kernel.org
http://linux.kernel.org/mailman/listinfo/stable

Reply via email to