Messages in this thread Patch in this message | | | Date | Fri, 05 Aug 2011 17:02:07 -0700 | From | Greg KH <> | Subject | [37/55] EHCI: only power off port if over-current is active |
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2.6.32-longterm review patch. If anyone has any objections, please let us know.
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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); } }
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