Commit 73519f68 authored by Uwe Kleine-König's avatar Uwe Kleine-König Committed by Zheng Zengkai
Browse files

pwm: lpc32xx: Don't modify HW state in .probe() after the PWM chip was registered

stable inclusion
from stable-5.10.69
commit 322b70b522abe03cd59712bb47a72eddd835d19d
bugzilla: 182675 https://gitee.com/openeuler/kernel/issues/I4I3ED

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=322b70b522abe03cd59712bb47a72eddd835d19d



--------------------------------

commit 3d2813fb upstream.

This fixes a race condition: After pwmchip_add() is called there might
already be a consumer and then modifying the hardware behind the
consumer's back is bad. So set the default before.

(Side-note: I don't know what this register setting actually does, if
this modifies the polarity there is an inconsistency because the
inversed polarity isn't considered if the PWM is already running during
.probe().)

Fixes: acfd92fd ("pwm: lpc32xx: Set PWM_PIN_LEVEL bit to default value")
Cc: Sylvain Lemieux <slemieux@tycoint.com>
Signed-off-by: default avatarUwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: default avatarThierry Reding <thierry.reding@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarChen Jun <chenjun102@huawei.com>
Acked-by: default avatarWeilong Chen <chenweilong@huawei.com>

Signed-off-by: default avatarChen Jun <chenjun102@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 73101a0a
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