Re: [PATCH 01/11] ASoC: dai_dma: remove slave_id field

From: Lars-Peter Clausen
Date: Mon Nov 15 2021 - 07:13:55 EST


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.

- Lars