Re: [PATCH] backlight: lp855x: Ensure regulators are disabled on probe failure
From: Jon Hunter
Date: Fri Mar 13 2020 - 10:16:24 EST
Hi Lee, Daniel,
On 24/02/2020 14:37, Daniel Thompson wrote:
> On Mon, Feb 24, 2020 at 02:07:48PM +0000, Jon Hunter wrote:
>> If probing the LP885x backlight fails after the regulators have been
>> enabled, then the following warning is seen when releasing the
>> regulators ...
>>
>> WARNING: CPU: 1 PID: 289 at drivers/regulator/core.c:2051 _regulator_put.part.28+0x158/0x160
>> Modules linked in: tegra_xudc lp855x_bl(+) host1x pwm_tegra ip_tables x_tables ipv6 nf_defrag_ipv6
>> CPU: 1 PID: 289 Comm: systemd-udevd Not tainted 5.6.0-rc2-next-20200224 #1
>> Hardware name: NVIDIA Jetson TX1 Developer Kit (DT)
>>
>> ...
>>
>> Call trace:
>> _regulator_put.part.28+0x158/0x160
>> regulator_put+0x34/0x50
>> devm_regulator_release+0x10/0x18
>> release_nodes+0x12c/0x230
>> devres_release_all+0x34/0x50
>> really_probe+0x1c0/0x370
>> driver_probe_device+0x58/0x100
>> device_driver_attach+0x6c/0x78
>> __driver_attach+0xb0/0xf0
>> bus_for_each_dev+0x68/0xc8
>> driver_attach+0x20/0x28
>> bus_add_driver+0x160/0x1f0
>> driver_register+0x60/0x110
>> i2c_register_driver+0x40/0x80
>> lp855x_driver_init+0x20/0x1000 [lp855x_bl]
>> do_one_initcall+0x58/0x1a0
>> do_init_module+0x54/0x1d0
>> load_module+0x1d80/0x21c8
>> __do_sys_finit_module+0xe8/0x100
>> __arm64_sys_finit_module+0x18/0x20
>> el0_svc_common.constprop.3+0xb0/0x168
>> do_el0_svc+0x20/0x98
>> el0_sync_handler+0xf4/0x1b0
>> el0_sync+0x140/0x180
>>
>> Fix this by ensuring that the regulators are disabled, if enabled, on
>> probe failure.
>>
>> Finally, ensure that the vddio regulator is disabled in the driver
>> remove handler.
>>
>> Signed-off-by: Jon Hunter <jonathanh@xxxxxxxxxx>
>
> Reviewed-by: Daniel Thompson <daniel.thompson@xxxxxxxxxx>
I received a bounce from Milo's email and so I am not sure that his
email address is still valid.
Can either of you pick this up?
Not sure if we should update the MAINTAINERS as well?
Jon
--
nvpublic