diff options
| author | Christian Engelmayer <christian.engelmayer@frequentis.com> | 2007-05-30 11:04:48 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-07-12 16:34:31 -0700 |
| commit | 756aa6b3d536afe85e151138cb03a293998887b3 (patch) | |
| tree | fd4b8d0efb2ef87bd4b3295086823246e76160f3 /drivers/usb/host | |
| parent | 648dcfc805ea1308552225e96113dc60e054f2f0 (diff) | |
| download | linux-756aa6b3d536afe85e151138cb03a293998887b3.tar.bz2 | |
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')
| -rw-r--r-- | drivers/usb/host/ehci-hub.c | 17 |
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) { |