On Tue, Jul 22, 2014 at 08:02:10PM -0400, James P Michels III wrote:
> This patch adds usb quirks to improve support for devices
> with non standard bInterval values. Quirks are added to support devices with
> bInterval values expressed as microframes or frames. The quirks cause the
> parse endpoint function to modify the reported bInterval to the standards
> conforming value.
>
> There is currently code in the endpoint parser that checks for bIntervals that are outside
> of the valid range (0-15 for USB 2+). In this case, the code assumes the bInterval is being
> reported in 1ms frames. However, the correction is only applied if the original bInterval
> value is out of the 0-15 range.
>
> With one of these quirks applied to the device, the bInterval will be accurately adjusted
> even when the misreported bInterval is in the 0-15 range.
>
> Signed-off-by: James P Michels III <james.p.michels@xxxxxxxxx>
> ---
> drivers/usb/core/config.c | 20 ++++++++++++++++++++
> drivers/usb/core/quirks.c | 4 ++++
> include/linux/usb/quirks.h | 13 +++++++++++++
> 3 files changed, 37 insertions(+)
>
> diff --git a/drivers/usb/core/config.c b/drivers/usb/core/config.c
> index 1ab4df1..1b343fe 100644
> --- a/drivers/usb/core/config.c
> +++ b/drivers/usb/core/config.c
> @@ -228,6 +228,26 @@ static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum,
> endpoint->desc.bInterval = n;
> }
>
> + /* Adjust bInterval reported as frames for quirked devices */
> + if (to_usb_device(ddev)->quirks & USB_QUIRK_INTERVAL_AS_FRAMES) {
> + endpoint->desc.bInterval = fls(d->bInterval * 8);
> + if (endpoint->desc.bInterval > 16)
> + endpoint->desc.bInterval = 16;
> + dev_warn(ddev, "bInterval adjusted from %d to %d\n",
> + d->bInterval,
> + endpoint->desc.bInterval);
> + }
But you don't add a device that uses this quirk, so why add it at all in
this patch? We don't add quirks that no one actually uses :)
thanks,
greg k-h
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