usb: gadget: uvc: fix interval_duration calculation

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commit 010dc57cb5 upstream.

According to USB specification:

  For full-/high-speed isochronous endpoints, the bInterval value is
  used as the exponent for a 2^(bInterval-1) value.

To correctly convert bInterval as interval_duration:
  interval_duration = 2^(bInterval-1) * frame_interval

Because the unit of video->interval is 100ns, add a comment info to
make it clear.

Fixes: 48dbe73117 ("usb: gadget: uvc: set req_size and n_requests based on the frame interval")
Cc: stable@vger.kernel.org
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
Link: https://patch.msgid.link/20260113-uvc-gadget-fix-patch-v2-2-62950ef5bcb5@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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This commit is contained in:

Xu Yang 2026-01-13 17:53:08 +08:00 • committed by Greg Kroah-Hartman

parent 34f6634dba

commit aee4732461

2 changed files with 6 additions and 3 deletions

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2

drivers/usb/gadget/function/uvc.h

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7

drivers/usb/gadget/function/uvc_video.c

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