From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E1C22415F14; Tue, 21 Jul 2026 19:20:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784661658; cv=none; b=kYppoHEd78JoxXbzupaoY2XYwbaSy5QC1nH7jGq/3emzS5z/1ZpkPnpuyn3RsE6l3raYq1iAdmO10hEC6uhayJZdt732LFXTaOl8thKthV6BP2vW//KltS2iSyfLsqPNBpw4skba17hTdyzL8FUAGRTcNAOrm/TH5oW05+k3z7I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784661658; c=relaxed/simple; bh=yTu7xItczuTyvLfyLO/3tHJOn70DNGbDnq692HAMbDw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=qze0IQNg2PHyeHXkINEOPtUQBEDYxKsnVVZvO6XfryvjseB4e9kL4eWitKESiNaxI63xbi0avIDk0c17R1crvnQksrO6zg2E3ppNcYNyXbq07cIrCsxZAoWgOl1QfhA/dtCKtX98UeaXz7CD13/mEoDcApzgOyHzM+uJ/YPgP3Y= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nZM9B7As; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nZM9B7As" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 254251F000E9; Tue, 21 Jul 2026 19:20:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784661656; bh=QiGzSRybyxpUKr6jwI5MemE5OSmbYEy3jXHzE2R61gA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=nZM9B7As4zHBzH75qCX3b7oVs/ThOTymGtvWDdIM2b1UNqEnkxhUL4K4rY5R/Yvqi dFCQwD7bc04BWptBmRJw4jN30cVz5MzOw5VNSZhZgkQlTC4w4pC7qkJ3/eAp2EWEjB jbMQcQMPMCc9ZXV9aze2wCc4WdLeYkmna/1r1ZFA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ronaldo Nunez , Frank Li , =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= , Sasha Levin Subject: [PATCH 6.12 0150/1276] pwm: imx27: Fix variable truncation in .apply() Date: Tue, 21 Jul 2026 17:09:53 +0200 Message-ID: <20260721152449.459645106@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152446.065700225@linuxfoundation.org> References: <20260721152446.065700225@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ronaldo Nunez [ Upstream commit dc9e08fdbcc3eb08a1d2b868b535081c44425e27 ] Fix a variable truncation when calculating period in microseconds as part of the solution for the ERR051198 in .apply() callback. Example scenario: - Period of 3us (PWMPR = 196 and prescaler = 1) - Expected value in tmp: 198000000000 (NSEC_PER_SEC * (196 + 2) * 1) - Actual value is 431504384 (truncation to u32) Signed-off-by: Ronaldo Nunez Reviewed-by: Frank Li Link: https://patch.msgid.link/20260522191348.6227-1-rnunez@baylibre.com Fixes: a25351e4c774 ("pwm: imx27: Workaround of the pwm output bug when decrease the duty cycle") Signed-off-by: Uwe Kleine-König Signed-off-by: Sasha Levin --- drivers/pwm/pwm-imx27.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/pwm/pwm-imx27.c b/drivers/pwm/pwm-imx27.c index 0375987194318f..32613165f2b3fa 100644 --- a/drivers/pwm/pwm-imx27.c +++ b/drivers/pwm/pwm-imx27.c @@ -220,7 +220,7 @@ static void pwm_imx27_wait_fifo_slot(struct pwm_chip *chip, static int pwm_imx27_apply(struct pwm_chip *chip, struct pwm_device *pwm, const struct pwm_state *state) { - unsigned long period_cycles, duty_cycles, prescale, period_us, tmp; + unsigned long period_cycles, duty_cycles, prescale, period_us; struct pwm_imx27_chip *imx = to_pwm_imx27_chip(chip); unsigned long long c; unsigned long long clkrate; @@ -228,6 +228,7 @@ static int pwm_imx27_apply(struct pwm_chip *chip, struct pwm_device *pwm, int val; int ret; u32 cr; + u64 tmp; clkrate = clk_get_rate(imx->clk_per); c = clkrate * state->period; @@ -269,6 +270,11 @@ static int pwm_imx27_apply(struct pwm_chip *chip, struct pwm_device *pwm, val = readl(imx->mmio_base + MX3_PWMPR); val = val >= MX3_PWMPR_MAX ? MX3_PWMPR_MAX : val; cr = readl(imx->mmio_base + MX3_PWMCR); + + /* + * tmp stores period in nanoseconds. Result fits in u64 since + * val <= 0xfffe and prescaler in [1, 0x1000]. + */ tmp = NSEC_PER_SEC * (u64)(val + 2) * MX3_PWMCR_PRESCALER_GET(cr); tmp = DIV_ROUND_UP_ULL(tmp, clkrate); period_us = DIV_ROUND_UP_ULL(tmp, 1000); -- 2.53.0