Re: [PATCH] usb: pci-quirks: do not access OHCI_FMINTERVAL register on ULI hw

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Tue, May 27, 2014 at 08:56:42AM +0400, Nikita Yushchenko wrote:
> This access causes hang on Freescale P2020DS board (that has OHCI
> provided by ULI 1533 chip).
> 
> Since preserving OHCI_FMINTERVAL was originally done only for NVIDIA
> hardware and only later (in c6187597) was turned unconditional, and
> c6187597 commit message again mentions only NVIDIA, I think it should be
> safe to disable preserving OHCI_FMINTERVAL if device vendor is ULI.

Have you tested this?

> Signed-off-by: Nikita Yushchenko <nyushchenko@dev.rtsoft.ru>
> ---
>  drivers/usb/host/pci-quirks.c |    8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
> index 00661d3..5acbd5b 100644
> --- a/drivers/usb/host/pci-quirks.c
> +++ b/drivers/usb/host/pci-quirks.c
> @@ -571,7 +571,7 @@ static void quirk_usb_handoff_ohci(struct pci_dev *pdev)
>  {
>  	void __iomem *base;
>  	u32 control;
> -	u32 fminterval;
> +	u32 uninitialized_var(fminterval);

Why is this change needed?  Sounds like a compiler bug to me :)

thanks,

greg k-h