Re: [PATCH 1/1] drivers/usb/host/pci-quirks.c: wait for EHCIhandoff far too long in quirk_usb_disable_ehci()

From: Andrew Morton
Date: Tue Sep 09 2008 - 00:45:15 EST



(cc linux-usb)

On Sat, 6 Sep 2008 17:29:53 -0700 Steven Noonan <steven.noonan@xxxxxxxxxxxxxx> wrote:

> This patch fixes a very noticeable bootup delay on some
> systems (in my particular case, an HP dv5178us). The
> problem is caused by a buggy BIOS which doesn't properly
> announce that the handoff was completed.
>
> The delay in the current version of pci-quirks.c is 5 seconds,
> which I've cut down to 0.5 seconds.
>
> Signed-off-by: Steven Noonan <steven@xxxxxxxxxxxxxx>
> ---
> drivers/usb/host/pci-quirks.c | 2 +-
> 1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
> index ae6e70e..9a3609a 100644
> --- a/drivers/usb/host/pci-quirks.c
> +++ b/drivers/usb/host/pci-quirks.c
> @@ -271,7 +271,7 @@ static void __devinit quirk_usb_disable_ehci(struct pci_dev *pdev)
> /* if boot firmware now owns EHCI, spin till
> * it hands it over.
> */
> - msec = 5000;
> + msec = 500;
> while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
> tried_handoff = 1;
> msleep(10);

I guess it risks breaking someone else's system. Or perhaps the number
was just grabbed out of the air.

Can we do a separate quirk just for that machine (and ones with the
same bug)?

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