From: Greg Kroah-Hartman Date: Mon, 24 Apr 2023 06:21:25 +0000 (+0200) Subject: 5.10-stable patches X-Git-Tag: v4.14.314~16 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=dea9aa336bbe9c8284394991b891b28e8b88419f;p=thirdparty%2Fkernel%2Fstable-queue.git 5.10-stable patches added patches: pwm-meson-explicitly-set-.polarity-in-.get_state.patch --- diff --git a/queue-5.10/pwm-meson-explicitly-set-.polarity-in-.get_state.patch b/queue-5.10/pwm-meson-explicitly-set-.polarity-in-.get_state.patch new file mode 100644 index 00000000000..27258fffd86 --- /dev/null +++ b/queue-5.10/pwm-meson-explicitly-set-.polarity-in-.get_state.patch @@ -0,0 +1,62 @@ +From 8caa81eb950cb2e9d2d6959b37d853162d197f57 Mon Sep 17 00:00:00 2001 +From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= +Date: Wed, 22 Mar 2023 22:45:44 +0100 +Subject: pwm: meson: Explicitly set .polarity in .get_state() +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +From: Uwe Kleine-König + +commit 8caa81eb950cb2e9d2d6959b37d853162d197f57 upstream. + +The driver only supports normal polarity. Complete the implementation of +.get_state() by setting .polarity accordingly. + +This fixes a regression that was possible since commit c73a3107624d +("pwm: Handle .get_state() failures") which stopped to zero-initialize +the state passed to the .get_state() callback. This was reported at +https://forum.odroid.com/viewtopic.php?f=177&t=46360 . While this was an +unintended side effect, the real issue is the driver's callback not +setting the polarity. + +There is a complicating fact, that the .apply() callback fakes support +for inversed polarity. This is not (and cannot) be matched by +.get_state(). As fixing this isn't easy, only point it out in a comment +to prevent authors of other drivers from copying that approach. + +Fixes: c375bcbaabdb ("pwm: meson: Read the full hardware state in meson_pwm_get_state()") +Reported-by: Munehisa Kamata +Acked-by: Martin Blumenstingl +Link: https://lore.kernel.org/r/20230310191405.2606296-1-u.kleine-koenig@pengutronix.de +Signed-off-by: Uwe Kleine-König +Signed-off-by: Thierry Reding +Signed-off-by: Uwe Kleine-König +Signed-off-by: Greg Kroah-Hartman +--- + drivers/pwm/pwm-meson.c | 7 +++++++ + 1 file changed, 7 insertions(+) + +--- a/drivers/pwm/pwm-meson.c ++++ b/drivers/pwm/pwm-meson.c +@@ -168,6 +168,12 @@ static int meson_pwm_calc(struct meson_p + duty = state->duty_cycle; + period = state->period; + ++ /* ++ * Note this is wrong. The result is an output wave that isn't really ++ * inverted and so is wrongly identified by .get_state as normal. ++ * Fixing this needs some care however as some machines might rely on ++ * this. ++ */ + if (state->polarity == PWM_POLARITY_INVERSED) + duty = period - duty; + +@@ -366,6 +372,7 @@ static void meson_pwm_get_state(struct p + state->period = 0; + state->duty_cycle = 0; + } ++ state->polarity = PWM_POLARITY_NORMAL; + } + + static const struct pwm_ops meson_pwm_ops = { diff --git a/queue-5.10/series b/queue-5.10/series index a15799d6361..7b474f2d2ad 100644 --- a/queue-5.10/series +++ b/queue-5.10/series @@ -60,3 +60,4 @@ tcp-udp-call-inet6_destroy_sock-in-ipv6-sk-sk_destruct.patch inet6-remove-inet6_destroy_sock-in-sk-sk_prot-destroy.patch dccp-call-inet6_destroy_sock-via-sk-sk_destruct.patch sctp-call-inet6_destroy_sock-via-sk-sk_destruct.patch +pwm-meson-explicitly-set-.polarity-in-.get_state.patch