[PATCH 3.19.y-ckt 022/102] usb: gadget: f_uac2: fix calculation of uac2->p_interval

[Kamal Mostafa]

3.19.8-ckt7 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Peter Chen <peter.chen@xxxxxxxxxxxxx>

commit c41b7767673cb76adeb2b5fde220209f717ea13c upstream.

The p_interval should be less if the 'bInterval' at the descriptor
is larger, eg, if 'bInterval' is 5 for HS, the p_interval should be
8000 / 16 = 500.

It fixes the patch 9bb87f168931 ("usb: gadget: f_uac2: send
reasonably sized packets")

Fixes: 9bb87f168931 ("usb: gadget: f_uac2: send reasonably sized packets")
Acked-by: Daniel Mack <zonque@xxxxxxxxx>
Signed-off-by: Peter Chen <peter.chen@xxxxxxxxxxxxx>
Signed-off-by: Felipe Balbi <balbi@xxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
 drivers/usb/gadget/function/f_uac2.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c
index 33e1665..df02947 100644
--- a/drivers/usb/gadget/function/f_uac2.c
+++ b/drivers/usb/gadget/function/f_uac2.c
@@ -1162,14 +1162,14 @@ afunc_set_alt(struct usb_function *fn, unsigned intf, unsigned alt)
 			factor = 1000;
 		} else {
 			ep_desc = &hs_epin_desc;
-			factor = 125;
+			factor = 8000;
 		}
 
 		/* pre-compute some values for iso_complete() */
 		uac2->p_framesize = opts->p_ssize *
 				    num_channels(opts->p_chmask);
 		rate = opts->p_srate * uac2->p_framesize;
-		uac2->p_interval = (1 << (ep_desc->bInterval - 1)) * factor;
+		uac2->p_interval = factor / (1 << (ep_desc->bInterval - 1));
 		uac2->p_pktsize = min_t(unsigned int, rate / uac2->p_interval,
 					prm->max_psize);
 
-- 
1.9.1

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