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Date: Tue, 13 Feb 2024 20:20:45 +0100
From: Miquel Raynal <miquel.raynal@bootlin.com>
To: Eric Curtin <ecurtin@redhat.com>
Cc: srinivas.kandagatla@linaro.org, gregkh@linuxfoundation.org,
 linux-kernel@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
 regressions@lists.linux.dev, =?UTF-8?B?UmFmYcWCIE1pxYJlY2tp?=
 <rafal@milecki.pl>, Chen-Yu Tsai <wenst@chromium.org>,
 asahi@lists.linux.dev, Sven Peter <sven@svenpeter.dev>
Subject: Re: [PATCH] nvmem: include bit index in cell sysfs file name
Message-ID: <20240213202045.1e823a6c@xps-13>
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References: <20240209163454.98051-1-srinivas.kandagatla@linaro.org>
	<CAOgh=FwFMaYvTwmqeOQrqHq2XANxghZbTuY3+SgFx_ozpysBOg@mail.gmail.com>
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Hi,

ecurtin@redhat.com wrote on Fri, 9 Feb 2024 16:49:22 +0000:

> On Fri, 9 Feb 2024 at 16:43, <srinivas.kandagatla@linaro.org> wrote:
> >
> > From: Arnd Bergmann <arnd@arndb.de>
> >
> > Creating sysfs files for all Cells caused a boot failure for linux-6.8-=
rc1 on
> > Apple M1, which (in downstream dts files) has multiple nvmem cells that=
 use the
> > same byte address. This causes the device probe to fail with
> >
> > [    0.605336] sysfs: cannot create duplicate filename '/devices/platfo=
rm/soc@200000000/2922bc000.efuse/apple_efuses_nvmem0/cells/efuse@a10'
> > [    0.605347] CPU: 7 PID: 1 Comm: swapper/0 Tainted: G S              =
   6.8.0-rc1-arnd-5+ #133
> > [    0.605355] Hardware name: Apple Mac Studio (M1 Ultra, 2022) (DT)
> > [    0.605362] Call trace:
> > [    0.605365]  show_stack+0x18/0x2c
> > [    0.605374]  dump_stack_lvl+0x60/0x80
> > [    0.605383]  dump_stack+0x18/0x24
> > [    0.605388]  sysfs_warn_dup+0x64/0x80
> > [    0.605395]  sysfs_add_bin_file_mode_ns+0xb0/0xd4
> > [    0.605402]  internal_create_group+0x268/0x404
> > [    0.605409]  sysfs_create_groups+0x38/0x94
> > [    0.605415]  devm_device_add_groups+0x50/0x94
> > [    0.605572]  nvmem_populate_sysfs_cells+0x180/0x1b0
> > [    0.605682]  nvmem_register+0x38c/0x470
> > [    0.605789]  devm_nvmem_register+0x1c/0x6c
> > [    0.605895]  apple_efuses_probe+0xe4/0x120
> > [    0.606000]  platform_probe+0xa8/0xd0
> >
> > As far as I can tell, this is a problem for any device with multiple ce=
lls on
> > different bits of the same address. Avoid the issue by changing the fil=
e name
> > to include the first bit number.
> >
> > Fixes: 0331c611949f ("nvmem: core: Expose cells through sysfs")
> > Link: https://github.com/AsahiLinux/linux/blob/bd0a1a7d4/arch/arm64/boo=
t/dts/apple/t600x-dieX.dtsi#L156
> > Cc: regressions@lists.linux.dev
> > Cc: Miquel Raynal <miquel.raynal@bootlin.com>
> > Cc: Rafa=C5=82 Mi=C5=82ecki <rafal@milecki.pl>
> > Cc: Chen-Yu Tsai <wenst@chromium.org>
> > Cc: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > Cc: asahi@lists.linux.dev
> > Cc: Sven Peter <sven@svenpeter.dev>
> > Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> > Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> =20
>=20

My R-by must have been lost, here it is again:

Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>

Thanks,
Miqu=C3=A8l