Re: [alsa-devel] [PATCH] soundwire: bus: fix device number leak on errors

From: Pierre-Louis Bossart
Date: Tue Jan 14 2020 - 12:48:30 EST




On 1/14/20 12:37 AM, Vinod Koul wrote:
On 13-01-20, 16:56, Pierre-Louis Bossart wrote:
If the programming of the dev_number fails due to an IO error, a new
device_number will be assigned, resulting in a leak.

Make sure we only assign a device_number once per Slave device.

Although I am not sure if this would be a leak, we assign a new num and
old number should have gotten recycled as they would be unattached
status.

When you program the device number and it fails, there is still a Device0 reporting as attached, so you will loop and try to assign a new device number. In this case there is never a transition to UNATTACHED, the Slave remains ATTACHED as Device0 until the enumeration succeed with a successful non-zero device number.

This only happened to us w/ early prototypes where the PCB routing was questionable and the speed too high, but still it's useful to keep this device number constant

Anyway this is good improvement as it helps to debug having same
dev_num, so Applied, thanks

Thanks.