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/platform/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 cells on
different bits of the same address. Avoid the issue by changing the file name
to include the first bit number.
Fixes: 0331c61194 ("nvmem: core: Expose cells through sysfs")
Link: https://github.com/AsahiLinux/linux/blob/bd0a1a7d4/arch/arm64/boot/dts/apple/t600x-dieX.dtsi#L156
Cc: <regressions@lists.linux.dev>
Cc: Miquel Raynal <miquel.raynal@bootlin.com>
Cc: Rafał Miłecki <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>
Reviewed-by: Eric Curtin <ecurtin@redhat.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/r/20240209163454.98051-1-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
e20f378d99