Re: [PATCH v2] usb/host/ehci-hub: Fix the issue EG20T USB hostcontroller has long resuming time, when pen drive is attached.

[Alan Stern]

On Thu, 12 Jul 2012, Tomoya MORINAGA wrote:

> Intel EG20T USB host controller does not send SOF in resuming time
> after suspending, if the FLR bit was not cleared. When pen drive is
> attached, the controller has a long resuming time to try re-connect
> it. This patch clear the FLR bit in suspending time for fixing the
> issue.
> 
> Signed-off-by: Tomoya MORINAGA <tomoya.rohm@xxxxxxxxx>
> ---
> v2: Update comments from Alan Stern
> 	Add patch description
> 	Always clear the STS_FLR flag.
> ---
>  drivers/usb/host/ehci-hub.c |    1 +
>  1 files changed, 1 insertions(+), 0 deletions(-)
> 
> diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
> index fc9e7cc..818a2f1 100644
> --- a/drivers/usb/host/ehci-hub.c
> +++ b/drivers/usb/host/ehci-hub.c
> @@ -318,6 +318,7 @@ static int ehci_bus_suspend (struct usb_hcd *hcd)
>  	ehci_readl(ehci, &ehci->regs->intr_enable);
>  
>  	ehci->next_statechange = jiffies + msecs_to_jiffies(10);
> +	ehci_writel(ehci, STS_FLR, &ehci->regs->status);
>  	spin_unlock_irq (&ehci->lock);

You need to add a comment to the code also.  Otherwise, a few years
from now somebody will see that line, realize it doesn't do anything
important, and get rid of it.

Alan Stern

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/