On Tue, 16 Oct 2012, Peter Chen wrote:
> Without this condition, all controllers will do this delay,
> and increase the resume time.
>
> Only enabled and unsuspended port needs this delay, but
> Some buggy hardware(like Synopsys usb controller) will
> clear suspend bit once they receive/send resume signal,
> so it takes resume bit as consideration.
>
> Tested it at Freescale i.mx6q Sabrelite board.
This can be improved a little bit.
> Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx>
> ---
> drivers/usb/host/ehci-hub.c | 22 +++++++++++++++++-----
> 1 files changed, 17 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
> index c788022..6505063 100644
> --- a/drivers/usb/host/ehci-hub.c
> +++ b/drivers/usb/host/ehci-hub.c
> @@ -384,11 +384,23 @@ static int ehci_bus_resume (struct usb_hcd *hcd)
> ehci_writel(ehci, ehci->command, &ehci->regs->command);
> ehci->rh_state = EHCI_RH_RUNNING;
>
> - /* Some controller/firmware combinations need a delay during which
> - * they set up the port statuses. See Bugzilla #8190. */
> - spin_unlock_irq(&ehci->lock);
> - msleep(8);
> - spin_lock_irq(&ehci->lock);
> + /*
> + * According to Bugzilla #8190, the port status for some controllers
> + * will be wrong without a delay. At their wrong status, the port
> + * is enabled, but not suspended neither resumed.
> + */
> + i = HCS_N_PORTS (ehci->hcs_params);
> + while (i--) {
> + temp = ehci_readl(ehci, &ehci->regs->port_status [i]);
No space before the '['.
> + if ((temp & PORT_PE) &&
> + !(temp & (PORT_SUSPEND | PORT_RESUME))) {
> + ehci_warn(ehci, "Port status(0x%x) is error\n", temp);
s/is error/is wrong/
Also, use ehci_dbg(), not ehci_warn(). This isn't an indication of a
failure so it doesn't need to be a warning.
> + spin_unlock_irq(&ehci->lock);
> + msleep(8);
> + spin_lock_irq(&ehci->lock);
Add "break;" here. You don't want to have multiple delays. :-)
> + }
> + }
> +
Alan Stern
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