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authorChristian Engelmayer <christian.engelmayer@frequentis.com>2007-05-30 11:04:48 -0700
committerGreg Kroah-Hartman <gregkh@suse.de>2007-07-12 16:34:31 -0700
commit756aa6b3d536afe85e151138cb03a293998887b3 (patch)
treefd4b8d0efb2ef87bd4b3295086823246e76160f3 /drivers/usb/host/ehci-hub.c
parent648dcfc805ea1308552225e96113dc60e054f2f0 (diff)
downloadlinux-linaro-stable-756aa6b3d536afe85e151138cb03a293998887b3.tar.gz
ehci-hub: improved over-current recovery
According to the USB Specification Revision 2.0 chapter 11.12.5 a hub experiencing an over-current condition must place all affected ports in the powered-off state. It seems that some root hubs need port power to be cycled by software in order to get back to normal functionality after an over-current condition ... like the EHCI implementation on an MPC8343E. Signed-off-by: Christian Engelmayer <christian.engelmayer@frequentis.com> Signed-off-by: David Brownell <david-b@pacbell.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/host/ehci-hub.c')
-rw-r--r--drivers/usb/host/ehci-hub.c17
1 files changed, 16 insertions, 1 deletions
diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 27291f502651..71aeca019e88 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -647,9 +647,24 @@ static int ehci_hub_control (
status |= 1 << USB_PORT_FEAT_C_CONNECTION;
if (temp & PORT_PEC)
status |= 1 << USB_PORT_FEAT_C_ENABLE;
- if ((temp & PORT_OCC) && !ignore_oc)
+
+ if ((temp & PORT_OCC) && !ignore_oc){
status |= 1 << USB_PORT_FEAT_C_OVER_CURRENT;
+ /*
+ * Hubs should disable port power on over-current.
+ * However, not all EHCI implementations do this
+ * automatically, even if they _do_ support per-port
+ * power switching; they're allowed to just limit the
+ * current. khubd will turn the power back on.
+ */
+ if (HCS_PPC (ehci->hcs_params)){
+ ehci_writel(ehci,
+ temp & ~(PORT_RWC_BITS | PORT_POWER),
+ status_reg);
+ }
+ }
+
/* whoever resumes must GetPortStatus to complete it!! */
if (temp & PORT_RESUME) {