Hi Jack,
Dne 04. 09. 21 v 9:40 Jack Pham napsal(a):
Hi Pavel,
On Mon, Aug 23, 2021 at 03:17:11PM +0200, Pavel Hofman wrote:
There is a problem with max packet size calculation for EP-IN. It has been
discussed here recently
https://www.spinics.net/lists/linux-usb/msg214615.html
The simple change in the post above fixed Win10 enumeration for me and
another tester.
I faced the same error on Win10 and also tried the above patch and it
worked for me as well. Are you planning to send a formal patch for it?
If so, you can add my
Tested-by: Jack Pham <jackp@xxxxxxxxxxxxxx>
Also, there is a problem with feedback value calculation which Win10 ignores
and keeps sending the same amount of samples. The fix is to send number of
samples per the actual packet, not per microframe for USB2. I have not
posted the attached patch as the whole patchset will most likely be reverted
for 5.15 https://www.spinics.net/lists/linux-usb/msg216042.html and I wanted
to wait till the situation works out to avoid confusion. In the attached
patch just change the ->c_srate_active to ->c_srate (the patch is on top of
more changes for switching between multiple samplerates).
It doesn't look like any of the feedback EP changes got reverted for
5.14 / 5.15-rc1 so it looks like the dust has settled. Are you going to
send the below patch formally as well?
Thanks for testing the patch. I did not want to intrude into Jerome's
plan. However, if Jerome is OK with the attached patch, I can submit it
formally and continue with submitting more patches for Win10 support.
Thanks,
Pavel.
>From 26f5a49c2ddac2d5c52c4072bc756e7d15b47bc8 Mon Sep 17 00:00:00 2001
From: Pavel Hofman <pavel.hofman@xxxxxxxxxxx>
Date: Mon, 6 Sep 2021 14:04:00 +0200
Subject: [PATCH] usb: gadget: f_uac2: fixed EP-IN wMaxPacketSize
Async feedback patches broke enumeration on Windows 10 previously fixed
by commit 789ea77310f0 ("usb: gadget: f_uac2: always increase endpoint
max_packet_size by one audio slot").
While the existing calculation for EP OUT capture for async mode yields
size+1 frame due to uac2_opts->fb_max > 0, playback side lost the +1
feature. Therefore the +1 frame addition must be re-introduced for
playback. Win10 enumerates the device only when both EP IN and EP OUT
max packet sizes are (at least) +1 frame.
Signed-off-by: Pavel Hofman <pavel.hofman@xxxxxxxxxxx>
Tested-by: Henrik Enquist <henrik.enquist@xxxxxxxxx>
Tested-by: Jack Pham <jackp@xxxxxxxxxxxxxx>
---
drivers/usb/gadget/function/f_uac2.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/gadget/function/f_uac2.c b/drivers/usb/gadget/function/f_uac2.c
index ae29ff2b2b68..bdc7e6e78455 100644
--- a/drivers/usb/gadget/function/f_uac2.c
+++ b/drivers/usb/gadget/function/f_uac2.c
@@ -584,11 +584,17 @@ static int set_ep_max_packet_size(const struct f_uac2_opts *uac2_opts,
ssize = uac2_opts->c_ssize;
}
- if (!is_playback && (uac2_opts->c_sync == USB_ENDPOINT_SYNC_ASYNC))
+ if (!is_playback && (uac2_opts->c_sync == USB_ENDPOINT_SYNC_ASYNC)) {
+ // Win10 requires max packet size + 1 frame
srate = srate * (1000 + uac2_opts->fb_max) / 1000;
-
- max_size_bw = num_channels(chmask) * ssize *
- DIV_ROUND_UP(srate, factor / (1 << (ep_desc->bInterval - 1)));
+ // updated srate is always bigger, therefore DIV_ROUND_UP always yields +1
+ max_size_bw = num_channels(chmask) * ssize *
+ (DIV_ROUND_UP(srate, factor / (1 << (ep_desc->bInterval - 1))));
+ } else {
+ // adding 1 frame provision for Win10
+ max_size_bw = num_channels(chmask) * ssize *
+ (DIV_ROUND_UP(srate, factor / (1 << (ep_desc->bInterval - 1))) + 1);
+ }
ep_desc->wMaxPacketSize = cpu_to_le16(min_t(u16, max_size_bw,
max_size_ep));
--
2.25.1
