linux-kernel - Re: [PATCH 1/3] ASoC: cs4271: Fix cs4271 I2C and SPI drivers automatic module loading

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20251017180313.0f0f71d7@bootlin.com>
Date: Fri, 17 Oct 2025 18:03:13 +0200
From: Herve Codina <herve.codina@...tlin.com>
To: Alexander Sverdlin <alexander.sverdlin@...il.com>
Cc: David Rhodes <david.rhodes@...rus.com>, Richard Fitzgerald	
 <rf@...nsource.cirrus.com>, Liam Girdwood <lgirdwood@...il.com>, Mark Brown
  <broonie@...nel.org>, Rob Herring <robh@...nel.org>, Krzysztof Kozlowski	
 <krzk+dt@...nel.org>, Conor Dooley <conor+dt@...nel.org>, Jaroslav Kysela	
 <perex@...ex.cz>, Takashi Iwai <tiwai@...e.com>, Nikita Shubin	
 <nikita.shubin@...uefel.me>, Axel Lin <axel.lin@...ics.com>, Brian Austin	
 <brian.austin@...rus.com>, linux-sound@...r.kernel.org,
 patches@...nsource.cirrus.com, devicetree@...r.kernel.org,
 linux-kernel@...r.kernel.org, Thomas Petazzoni
 <thomas.petazzoni@...tlin.com>
Subject: Re: [PATCH 1/3] ASoC: cs4271: Fix cs4271 I2C and SPI drivers
 automatic module loading

Hi Alexander,

On Fri, 17 Oct 2025 17:35:56 +0200
Alexander Sverdlin <alexander.sverdlin@...il.com> wrote:

> Hi Herve,
> 
> On Fri, 2025-10-17 at 17:10 +0200, Herve Codina wrote:
> > > > > > In order to have the I2C or the SPI module loaded automatically, move
> > > > > > the MODULE_DEVICE_TABLE(of, ...) the core to I2C and SPI parts.
> > > > > > Also move cs4271_dt_ids itself from the core part to I2C and SPI parts
> > > > > > as both the call to MODULE_DEVICE_TABLE(of, ...) and the cs4271_dt_ids
> > > > > > table itself need to be in the same file.      
> > > > > 
> > > > > I'm a bit confused by this change.
> > > > > What do you have in SYSFS "uevent" entry for the real device?    
> > > > 
> > > > Here is my uevent content:
> > > > --- 8<---
> > > > # cat /sys/bus/i2c/devices/3-0010/uevent 
> > > > DRIVER=cs4271
> > > > OF_NAME=cs4271
> > > > OF_FULLNAME=/i2c@...30000/cs4271@10
> > > > OF_COMPATIBLE_0=cirrus,cs4271
> > > > OF_COMPATIBLE_N=1
> > > > MODALIAS=of:Ncs4271T(null)Ccirrus,cs4271
> > > > # 
> > > > --- 8< ---    
> > > 
> > > that's what I get with SPI-connected CS4271, and this is actually what I'd
> > > expect (linux-next as of 2433b8476165):
> > > 
> > > # cat /sys/bus/spi/devices/spi0.0/uevent
> > > DRIVER=cs4271
> > > OF_NAME=codec
> > > OF_FULLNAME=/soc/spi@...a0000/codec@0
> > > OF_COMPATIBLE_0=cirrus,cs4271
> > > OF_COMPATIBLE_N=1
> > > MODALIAS=spi:cs4271  
> > 
> > So, this is without my patch applied.  
> 
> this is the modalias of the device, it doesn't depend on your patch series.
> 
> I'd say that modalias for SPI device is correct but commit c973b8a7dc50
> lacks MODULE_DEVICE_TABLE(spi, ...) in the driver.
> 
> I'd argue that I2C modalias is correct in the driver:
> 
> # modinfo snd-soc-cs4271-i2c
> ...
> alias:          i2c:cs4271
> 
> But I still have to understand what happened to I2C core.
> 
> > I don't have any CS4271 connected on SPI bus to perform the same test
> > with my patch applied.  
> 

In my next iteration, I will fix the MODULE_DEVICE_TABLE() in cs4271-spi.c
replacing
  MODULE_DEVICE_TABLE(of, cs4271_dt_ids);
by
  MODULE_DEVICE_TABLE(spi, cs4271_dt_ids);

For the moment, related to I2C, I keep MODULE_DEVICE_TABLE(of, cs4271_dt_ids)
in cs4271-i2c.c

Best regards,
Hervé