RE: [PATCH 12/22] ASoC: rsnd: Update SSI for RZ/G3E support

[John Madieu]

Hi Geert,

Thanks you for testing and reporting this.

> -----Original Message-----
> From: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> Sent: Tuesday, March 24, 2026 2:37 PM
> To: John Madieu <john.madieu.xa@xxxxxxxxxxxxxx>
> Subject: Re: [PATCH 12/22] ASoC: rsnd: Update SSI for RZ/G3E support
> 
> Hi John,
> 
> On Thu, 19 Mar 2026 at 16:56, John Madieu <john.madieu.xa@xxxxxxxxxxxxxx>
> wrote:
> > Add SSI support for the Renesas RZ/G3E SoC, which differs from earlier
> > generations in several ways:
> >
> >  - The SSI block always operates in BUSIF mode; RZ/G3E does not
> implement
> >    the SSITDR/SSIRDR registers used by R-Car Gen2/Gen3/Gen4 for direct
> SSI
> >    DMA.
> >    Consequently, all audio data must pass through BUSIF.
> >  - Each SSI instance has its own reset line, exposed using per-SSI names
> >    such as "ssi0", "ssi1", etc., rather than a single shared reset.
> >
> > To support these differences, update rsnd_ssi_use_busif() to always
> > return 1 on RZ/G3E, ensuring that the driver consistently selects the
> > BUSIF DMA path. Also update the reset acquisition logic to request the
> > appropriate per-SSI reset controller based on the SSI instance name.
> >
> > Signed-off-by: John Madieu <john.madieu.xa@xxxxxxxxxxxxxx>
> 
> Thanks for your patch!
> 
> > --- a/sound/soc/renesas/rcar/ssi.c
> > +++ b/sound/soc/renesas/rcar/ssi.c
> > @@ -123,8 +123,15 @@ int rsnd_ssi_use_busif(struct rsnd_dai_stream
> > *io)  {
> >         struct rsnd_mod *mod = rsnd_io_to_mod_ssi(io);
> >         struct rsnd_ssi *ssi = rsnd_mod_to_ssi(mod);
> > +       struct rsnd_priv *priv = rsnd_mod_to_priv(mod);
> >         int use_busif = 0;
> >
> > +       /*
> > +        * RZ/G3E does not support PIO mode. Always use BUSIF.
> > +        */
> > +       if (rsnd_flags_has(priv, RSND_SSI_ALWAYS_BUSIF))
> > +               return 1;
> > +
> >         if (!rsnd_ssi_is_dma_mode(mod))
> >                 return 0;
> >
> > @@ -865,6 +872,8 @@ static int rsnd_ssi_common_remove(struct rsnd_mod
> *mod,
> >                 rsnd_flags_del(ssi, RSND_SSI_PROBED);
> >         }
> >
> > +       rsnd_dma_detach(io, mod, &io->dma);
> 
> This goes BOOM on R-Car Gen3 and Gen4:

Sorry for the breakage, I should get rid of this in
v2.

Regards,
John

> 
>     Unable to handle kernel NULL pointer dereference at virtual address
> 0000000000000004
>     Mem abort info:
>       ESR = 0x0000000096000004
>       EC = 0x25: DABT (current EL), IL = 32 bits
>       SET = 0, FnV = 0
>       EA = 0, S1PTW = 0
>       FSC = 0x04: level 0 translation fault
>     Data abort info:
>       ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
>       CM = 0, WnR = 0, TnD = 0, TagAccess = 0
>       GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
>     [0000000000000004] user address but active_mm is swapper
>     Internal error: Oops: 0000000096000004 [#1]  SMP
>     CPU: 1 UID: 0 PID: 1 Comm: swapper/0 Not tainted 7.0.0-rc5-arm64-
> renesas-07233-g377893124b8a #3530 PREEMPT
>     Hardware name: Renesas Gray Hawk Single board based on r8a779h0 (DT)
>     pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>     pc : rsnd_dma_detach+0x10/0x20
>     lr : rsnd_ssi_common_remove+0x48/0x74
>     sp : ffff8000818ebac0
>     x29: ffff8000818ebac0 x28: ffff000441c02938 x27: ffff0004408a8410
>     x26: 000000000000000d x25: 0000000000000000 x24: ffff8000817b9970
>     x23: 0000000000000000 x22: 000000000000000c x21: 00000000fffffdfb
>     x20: ffff000441c02938 x19: ffff0004402bc080 x18: 00000000ffffffff
>     x17: ffff000440ba6600 x16: ffff000440ba6a00 x15: ffff8000818eb700
>     x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000030
>     x11: 0101010101010101 x10: ffff800080fa7670 x9 : 1fffe00088052d21
>     x8 : 0101010101010101 x7 : 7f7f7f7f7f7f7f7f x6 : feff636d746e722d
>     x5 : 000000000000003c x4 : ffff800080a9dcc4 x3 : ffff0004402be800
>     x2 : ffff000441c029b8 x1 : ffff000441c02938 x0 : 0000000000000000
>     Call trace:
>      rsnd_dma_detach+0x10/0x20 (P)
>      rsnd_ssi_common_remove+0x48/0x74
>      rsnd_probe+0x2d0/0x448
>      platform_probe+0x58/0x90
>      really_probe+0xb8/0x294
>      __driver_probe_device+0x74/0x124
>      driver_probe_device+0x3c/0x158
>      __driver_attach+0xe0/0x1b4
>      bus_for_each_dev+0x78/0xd4
>      driver_attach+0x20/0x28
>      bus_add_driver+0xe0/0x1e0
>      driver_register+0x58/0x114
>      __platform_driver_register+0x20/0x28
>      rsnd_driver_init+0x18/0x20
>      do_one_initcall+0x7c/0x184
>      kernel_init_freeable+0x200/0x2e0
>      kernel_init+0x20/0x1cc
>      ret_from_fork+0x10/0x20
>     Code: a9bf7bfd aa0003e1 910003fd f9400040 (b9400402)
>     ---[ end trace 0000000000000000 ]---
> 
> > +
> >         return 0;
> >  }
> >
> 
> Gr{oetje,eeting}s,
> 
>                         Geert
> 
> --
> Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-
> m68k.org
> 
> In personal conversations with technical people, I call myself a hacker.
> But when I'm talking to journalists I just say "programmer" or something
> like that.
>                                 -- Linus Torvalds