2022-11-04 08:01:33

by Ai Chao

Subject: [PATCH] ALSA: usb-audio: fix Hamedal C20 usb camero disconnect issue

For Hamedal C20, the current rate is different from the runtime rate,
snd_usb_endpoint stop and close endpoint to resetting rate.
if snd_usb_endpoint close the endpoint, sometimes usb will
disconnect the device.

Signed-off-by: aichao <[email protected]>
---
sound/usb/endpoint.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 533919a28856..c19e420b1780 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -825,7 +825,9 @@ void snd_usb_endpoint_close(struct snd_usb_audio *chip,
usb_audio_dbg(chip, "Closing EP 0x%x (count %d)\n",
ep->ep_num, ep->opened);

- if (!--ep->iface_ref->opened)
+ if (!--ep->iface_ref->opened
+ && (le16_to_cpu(chip->dev->descriptor.idVendor) != 0x0525)
+ && (le16_to_cpu(chip->dev->descriptor.idProduct) != 0xa4ad))
endpoint_set_interface(chip, ep, false);

if (!--ep->opened) {
--
2.25.1

2022-11-04 08:58:53

by Takashi Iwai

Subject: Re: [PATCH] ALSA: usb-audio: fix Hamedal C20 usb camero disconnect issue

On Fri, 04 Nov 2022 08:35:18 +0100,
aichao wrote:
>
> For Hamedal C20, the current rate is different from the runtime rate,
> snd_usb_endpoint stop and close endpoint to resetting rate.
> if snd_usb_endpoint close the endpoint, sometimes usb will
> disconnect the device.
>
> Signed-off-by: aichao <[email protected]>

OK, this is more understandable than the previous one.

But it doesn't look like a proper workaround, and we need to figure
out the culprit more deeply. The interface is anyway reset once when
the parameter is changed / re-setup. Doesn't it hit the same problem?
Or it's about clearing the interface and keep it for long time?

In anyway, please give lsusb -v output of the device.

BTW, is aichao your full name? The sign-off must be with the real
full name, and it's a legal requirement.


thanks,

Takashi


> ---
> sound/usb/endpoint.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
> index 533919a28856..c19e420b1780 100644
> --- a/sound/usb/endpoint.c
> +++ b/sound/usb/endpoint.c
> @@ -825,7 +825,9 @@ void snd_usb_endpoint_close(struct snd_usb_audio *chip,
> usb_audio_dbg(chip, "Closing EP 0x%x (count %d)\n",
> ep->ep_num, ep->opened);
>
> - if (!--ep->iface_ref->opened)
> + if (!--ep->iface_ref->opened
> + && (le16_to_cpu(chip->dev->descriptor.idVendor) != 0x0525)
> + && (le16_to_cpu(chip->dev->descriptor.idProduct) != 0xa4ad))
> endpoint_set_interface(chip, ep, false);
>
> if (!--ep->opened) {
> --
> 2.25.1
>