On Fri, 21 Oct 2016, Sriram Dash wrote:
> For the USB3.0 controller, USB 2.0 reset not driven while
> port is in Resume state. So, do not program the USB 2.0 reset
> (PORTSC[PR]=1) while in Resume state.
>
> Signed-off-by: Rajat Srivastava <rajat.srivastava@xxxxxxx>
> Signed-off-by: Sriram Dash <sriram.dash@xxxxxxx>
> Signed-off-by: Rajesh Bhagat <rajesh.bhagat@xxxxxxx>
> ---
> drivers/usb/host/xhci-hub.c | 28 +++++++++++++++++++++++++++-
> drivers/usb/host/xhci.h | 1 +
> 2 files changed, 28 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
> index 730b9fd..3def0dd 100644
> --- a/drivers/usb/host/xhci-hub.c
> +++ b/drivers/usb/host/xhci-hub.c
> @@ -878,7 +878,7 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
> struct xhci_hcd *xhci = hcd_to_xhci(hcd);
> int max_ports;
> unsigned long flags;
> - u32 temp, status;
> + u32 temp, status, tmp_status = 0;
> int retval = 0;
> __le32 __iomem **port_array;
> int slot_id;
> @@ -1098,6 +1098,32 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
> spin_lock_irqsave(&xhci->lock, flags);
> break;
> case USB_PORT_FEAT_RESET:
> + /*
> + * Erratum : A010129
> + * Synopsys STAR 9000962562.
> + * USB 2.0 Reset Not Driven While Port in Resume
> + * While in USB 2.0 resume state (the PORTSC.PLS
> + * register bit is set to 4'd15), if the xHCI driver
> + * programs the PORTSC.PR register bit to 1, the
> + * controller does not drive a USB 2.0 reset
> + * and it does not generate a PORTSC.PRC=1 interrupt.
> + * So, The xHCI driver should not program a USB
> + * 2.0 reset (PORTSC.PR=1) while in resume
> + * (PORTSC.PLS=4'd15).
> + */
> + if (xhci->quirks & XHCI_PORT_RST_ON_RESUME) {
It's always a bad idea to drive a reset signal while a port is
resuming. We don't need a quirk flag for this. The HCD should never
do it, and the USB core should never tell the HCD to do it.
Alan Stern
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