From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8E44C7618E for ; Sat, 22 Apr 2023 15:59:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229575AbjDVP75 (ORCPT ); Sat, 22 Apr 2023 11:59:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43184 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229555AbjDVP75 (ORCPT ); Sat, 22 Apr 2023 11:59:57 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36A6E10EA for ; Sat, 22 Apr 2023 08:59:56 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BA94960B76 for ; Sat, 22 Apr 2023 15:59:55 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C404EC433EF; Sat, 22 Apr 2023 15:59:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1682179195; bh=u17G5wqbbqqRp1CN8C3vSpMIgGNnmE8AKqyxcWYGGyg=; h=Subject:To:Cc:From:Date:From; b=KQInsCWa1rYDkFOKahlT5O2CeZ3VfE3FBgwppJtk8Iy8kbZNif72wUfUp18cNBCCh +0psmau8+6JH56Zc7g7mcW4KXJVFyafcFWuKBBIfJcaWFKDzxRKYjFzZf+HxTnRcyT xH4EcJQqOhcaUBPteyB7tOpdwCnWO/WK1tEOG/EI= Subject: FAILED: patch "[PATCH] pwm: meson: Explicitly set .polarity in .get_state()" failed to apply to 5.15-stable tree To: u.kleine-koenig@pengutronix.de, kamatam@amazon.com, martin.blumenstingl@googlemail.com, thierry.reding@gmail.com Cc: From: Date: Sat, 22 Apr 2023 17:59:44 +0200 Message-ID: <2023042244-audience-anemic-4b09@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x 8caa81eb950cb2e9d2d6959b37d853162d197f57 # git commit -s git send-email --to '' --in-reply-to '2023042244-audience-anemic-4b09@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: 8caa81eb950c ("pwm: meson: Explicitly set .polarity in .get_state()") 6c452cff79f8 ("pwm: Make .get_state() callback return an error code") 8eca6b0a647a ("Merge tag 'pwm/for-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >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: [PATCH] pwm: meson: Explicitly set .polarity in .get_state() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c index 16d79ca5d8f5..5cd7b90872c6 100644 --- a/drivers/pwm/pwm-meson.c +++ b/drivers/pwm/pwm-meson.c @@ -162,6 +162,12 @@ static int meson_pwm_calc(struct meson_pwm *meson, struct pwm_device *pwm, 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; @@ -358,6 +364,8 @@ static int meson_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, state->duty_cycle = 0; } + state->polarity = PWM_POLARITY_NORMAL; + return 0; }