| From 81463c1d707186adbbe534016cd1249edeab0dac Mon Sep 17 00:00:00 2001 |
| From: Sergei Shtylyov <sshtylyov@ru.mvista.com> |
| Date: Wed, 6 Jul 2011 23:19:38 +0400 |
| Subject: EHCI: only power off port if over-current is active |
| |
| From: Sergei Shtylyov <sshtylyov@ru.mvista.com> |
| |
| commit 81463c1d707186adbbe534016cd1249edeab0dac upstream. |
| |
| 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 <sshtylyov@ru.mvista.com> |
| Acked-by: Alan Stern <stern@rowland.harvard.edu> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
| |
| --- |
| drivers/usb/host/ehci-hub.c | 3 ++- |
| 1 file changed, 2 insertions(+), 1 deletion(-) |
| |
| --- a/drivers/usb/host/ehci-hub.c |
| +++ b/drivers/usb/host/ehci-hub.c |
| @@ -758,10 +758,11 @@ 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); |
| } |
| } |
| |
