The 3d9545cc375d117554a9b35dfddadf9189c62775(EHCI: maintain the ehci->command value properly) introducs one command register configuration lost problem by the below line in ehci_reset: ehci->command = ehci_readl(ehci, &ehci->regs->command); After writting RESET into command register, it is restored to its default value per EHCI spec[1], so the previous configuration will be lost, and may introduce some problems reported recently: - imx51 Babbage board detect usb hub failed[2], reported by Richard Zhao. - mouse and keyboard hangs in linux-next found by Dan Carpenter and Greg-KH. So this patch just removes the line to fix these problems, and keep configurating command register consistent as before the commit 3d9545cc(EHCI: maintain the ehci->command value properly). [1], 4.1 Host Controller Initialization of EHCI Specification 1.0 [2], failed dmesg log: usb 1-1: new high-speed USB device number 2 using mxc-ehci hub 1-1:1.0: USB hub found hub 1-1:1.0: 7 ports detected mxc-ehci mxc-ehci.1: fatal error mxc-ehci mxc-ehci.1: HC died; cleaning up mxc-ehci mxc-ehci.1: force halt; handshake f5780344 00004000 00004000 -> -110 mxc-ehci mxc-ehci.1: HC died; cleaning up usb 1-1: USB disconnect, device number 2 Reported-by: Richard Zhao <richard.zhao@xxxxxxxxxxxxx> Cc: Chen Peter-B29397 <B29397@xxxxxxxxxxxxx> Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> Cc: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxxxxx> --- drivers/usb/host/ehci-hcd.c | 1 - 1 file changed, 1 deletion(-) diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c index f644ba9..5597e60 100644 --- a/drivers/usb/host/ehci-hcd.c +++ b/drivers/usb/host/ehci-hcd.c @@ -352,7 +352,6 @@ static int ehci_reset (struct ehci_hcd *ehci) if (ehci->debug) dbgp_external_startup(); - ehci->command = ehci_readl(ehci, &ehci->regs->command); ehci->port_c_suspend = ehci->suspended_ports = ehci->resuming_ports = 0; return retval; -- 1.7.9.5 -- 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
