On Thu, 3 Oct 2024 23:19:16 +0800
Chen-Yu Tsai <wens@xxxxxxxx> wrote:
> On Thu, Oct 3, 2024 at 7:15 PM Andre Przywara <andre.przywara@xxxxxxx> wrote:
> >
> > At the moment trying to register a second AXP chip makes the probe fail,
> > as some sysfs registration fails due to a duplicate name:
> >
> > ...
> > [ 3.688215] axp20x-i2c 0-0035: AXP20X driver loaded
> > [ 3.695610] axp20x-i2c 0-0036: AXP20x variant AXP323 found
> > [ 3.706151] sysfs: cannot create duplicate filename '/bus/platform/devices/axp20x-regulator'
> > [ 3.714718] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.12.0-rc1-00026-g50bf2e2c079d-dirty #192
> > [ 3.724020] Hardware name: Avaota A1 (DT)
> > [ 3.728029] Call trace:
> > [ 3.730477] dump_backtrace+0x94/0xec
> > [ 3.734146] show_stack+0x18/0x24
> > [ 3.737462] dump_stack_lvl+0x80/0xf4
> > [ 3.741128] dump_stack+0x18/0x24
> > [ 3.744444] sysfs_warn_dup+0x64/0x80
> > [ 3.748109] sysfs_do_create_link_sd+0xf0/0xf8
> > [ 3.752553] sysfs_create_link+0x20/0x40
> > [ 3.756476] bus_add_device+0x64/0x104
> > [ 3.760229] device_add+0x310/0x760
> > [ 3.763717] platform_device_add+0x10c/0x238
> > [ 3.767990] mfd_add_device+0x4ec/0x5c8
> > [ 3.771829] mfd_add_devices+0x88/0x11c
> > [ 3.775666] axp20x_device_probe+0x70/0x184
> > [ 3.779851] axp20x_i2c_probe+0x9c/0xd8
> > ...
> >
> > This is because we use PLATFORM_DEVID_NONE for the mfd_add_devices()
> > call, which would number the child devices in the same 0-based way, even
> > for the second (or any other) instance.
> >
> > Use PLATFORM_DEVID_AUTO instead, which automatically assigns
> > non-conflicting device numbers.
>
> That's weird... I don't remember running into this when working on the A80,
> which had two albeit different AXP chips. That was a long time ago though.
So I tested this on a Cubieboard 4, and it works there either way,
with or without this patch. That's RSB instead of I2C, which honestly
shouldn't make much of a difference, but maybe the call path differs?
But since it still works, I think this patch is correct regardless.
Thanks,
Andre
> > Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
>
> Reviewed-by: Chen-Yu Tsai <wens@xxxxxxxx>
>
> > ---
> > drivers/mfd/axp20x.c | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c
> > index 5ceea359289f..bc08ae433260 100644
> > --- a/drivers/mfd/axp20x.c
> > +++ b/drivers/mfd/axp20x.c
> > @@ -1419,7 +1419,7 @@ int axp20x_device_probe(struct axp20x_dev *axp20x)
> > }
> > }
> >
> > - ret = mfd_add_devices(axp20x->dev, -1, axp20x->cells,
> > + ret = mfd_add_devices(axp20x->dev, PLATFORM_DEVID_AUTO, axp20x->cells,
> > axp20x->nr_cells, NULL, 0, NULL);
> >
> > if (ret) {
> > --
> > 2.25.1
> >
>
