Re: [PATCH] nvmem: include bit index in cell sysfs file name
From: Greg KH
Date: Wed Feb 14 2024 - 10:29:02 EST
On Fri, Feb 09, 2024 at 04:34:54PM +0000, srinivas.kandagatla@xxxxxxxxxx wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
>
> 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: 0331c611949f ("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@xxxxxxxxxxxxxxx
> Cc: Miquel Raynal <miquel.raynal@xxxxxxxxxxx>
> Cc: Rafał Miłecki <rafal@xxxxxxxxxx>
> Cc: Chen-Yu Tsai <wenst@xxxxxxxxxxxx>
> Cc: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: asahi@xxxxxxxxxxxxxxx
> Cc: Sven Peter <sven@xxxxxxxxxxxxx>
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> ---
> Hi Greg,
>
> Here is a fix in nvmem for 6.8, could you queue these for next possible rc.
>
> Did not cc Stable as this is only targeted for 6.8 and no backporting is
> required.
Sorry for the delay, now queued up.
greg k-h