15.11.2021 14:53, Lars-Peter Clausen пишет: > On 11/15/21 11:42 AM, Arnd Bergmann wrote: >> On Mon, Nov 15, 2021 at 11:14 AM Lars-Peter Clausen <lars@xxxxxxxxxx> >> wrote: >>> On 11/15/21 9:53 AM, Arnd Bergmann wrote: >>>> From: Arnd Bergmann <arnd@xxxxxxxx> >>>> >>>> This field is never set, and serves no purpose, so remove it. >>> I agree that we should remove it. Its been legacy support code for a >>> while, but the description that there is no user is not right. >>> >>> The tegra20_spdif driver obviously uses it and that user is removed in >>> this patch. I think it makes sense to split that out into a separate >>> patch with a description why the driver will still work even with >>> slave_id removed. Maybe the best is to remove the whole tegra20_spdif >>> driver. >> Ok, I'll split out the tegra patch and try to come up with a better >> description for it. What I saw in that driver is it just passes down the >> slave_id number from a 'struct resource', but there is nothing in >> the kernel that sets up this resource. >> >> Do you or someone else have more information on the state of this >> driver? I can see that it does not contain any of_device_id based >> probing, so it seems that this is either dead code, the platform_device >> gets created by some other code that is no longer compatible with >> this driver. > > I've looked into this a while back, when I tried to remove slave_id. And > as far as I can tell there were never any in-tree users of this driver, > even back when we used platform board files. Maybe somebody from Nvidia > knows if there are out-of-tree users. That Tegra SPDIF driver was never used. Still there is a growing interest nowadays in making it alive by implementing HDMI audio support for Tegra20 SoC. It was on my todo list for a long time, I'll try to prioritize that work 5.17, it shouldn't take much effort. The slave_id should be removed anyways, it won't be needed.