On Mon, 5 Jan 2015, Lucas Stach wrote: > Some controllers need to have external power supplied before toggling > the internal PORT_POWER bit. > > Fixes: 11a7e5940514 (usb: ehci: add ehci_port_power interface) on i.MX51 > where the controller would hang the machine when trying to enable PORT_POWER. > > Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx> > Cc: stable@xxxxxxxxxxxxxxx [3.18+] > --- > drivers/usb/host/ehci-hub.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c > index 118edb7bdca2..aad5b3b32d0e 100644 > --- a/drivers/usb/host/ehci-hub.c > +++ b/drivers/usb/host/ehci-hub.c > @@ -1306,13 +1306,13 @@ static int ehci_port_power(struct ehci_hcd *ehci, int portnum, bool enable) > u32 __iomem *status_reg = &ehci->regs->port_status[portnum]; > u32 temp = ehci_readl(ehci, status_reg) & ~PORT_RWC_BITS; > > + if (hcd->driver->port_power) > + hcd->driver->port_power(hcd, portnum, enable); > + > if (enable) > ehci_writel(ehci, temp | PORT_POWER, status_reg); > else > ehci_writel(ehci, temp & ~PORT_POWER, status_reg); > > - if (hcd->driver->port_power) > - hcd->driver->port_power(hcd, portnum, enable); > - > return 0; > } This comment may not be relevant any more, but... It seems to me that what you really want to do is call the driver's override routine _before_ turning _on_ the PORT_POWER bit and _after_ turning that bit _off_. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
