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 9B0523AFAEA; Sat, 12 Sep 2026 19:04:43 +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=1789239885; cv=none; b=rms4jRXpMaukPmbkgqly1SRTTssMtStyTXms9xAbr/iTBloD5VrahgGHU7+ztX83t5j440D5TXpq0HxnEiHFsALQ595LB1SBwLCkO4mPRQgTwwIZVphFhP3Z//KDt1FDiUOetoM3yJ/9bT4WhAyVKKzgi9Be4Bx4EPuyJlfEXv8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789239885; c=relaxed/simple; bh=qdHma/xd9l9y5ds4aA8mPOywK1U4jhHu033FU+MZ/J8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cGuHClh955TaUP6ykPcu2q3jmXCTaP+IBE105DqsN8LJ6X5Y8f8oIBa/K/r5f1wtytT7iHhwEIb3AwSnyfaboKwPN9KwPb1VJ8zniqQ5WyBvzPJcoEc1kCpFqop/t1Vf/4JWMO5UUi4MIf8dDG5bVES9DMSLW7U5nrGPyVTjRN8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=PT4UcjAV; 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="PT4UcjAV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B3D891F000FF; Sat, 12 Sep 2026 19:04:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789239882; bh=0r3CcjUkvCce/W9lLIPvAf19ox+hTA++yOLbXGCzUsM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=PT4UcjAV57nLLihoquUAry0m0WKbH6K5/RrmK5lUFbDQDc+uOAmNzi/Scm3ZzRsmf OTY6Ukzv08Cj5pXlCe7qiVVnuBeWKa3GBSOohD+R7hhkx495uRdpqRomHCwjZi1m6y ioQ4EA+MDHUH6LD/zSxzmA8ipuI+Vv3VTtzYaJQM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Nikhil Gautam , Jonathan Cameron , Sasha Levin Subject: [PATCH 5.15 754/935] iio: light: gp2ap002: Fix unbalanced runtime PM on repeated event writes Date: Sat, 12 Sep 2026 09:03:04 +0200 Message-ID: <20260912065544.126780238@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065526.833703348@linuxfoundation.org> References: <20260912065526.833703348@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-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Nikhil Gautam [ Upstream commit 579c049b4cb6fc72ce2c505fc5334540be0efcd3 ] The IIO core does not filter duplicate writes to the event enable attribute, so writing the same value twice invokes write_event_config() twice. Enabling twice leaks a runtime PM reference, preventing the device from ever suspending again; disabling twice underflows the usage count and triggers a "Runtime PM usage count underflow" warning. Bail out early when the requested state matches the current state. While at it, switch to pm_runtime_resume_and_get() so a failed resume is propagated to userspace instead of silently marking the event enabled. Fixes: 97d642e23037c ("iio: light: Add a driver for Sharp GP2AP002x00F") Signed-off-by: Nikhil Gautam Signed-off-by: Jonathan Cameron Signed-off-by: Sasha Levin --- drivers/iio/light/gp2ap002.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/iio/light/gp2ap002.c b/drivers/iio/light/gp2ap002.c index 46a5367f7ce9e..430edce1057e2 100644 --- a/drivers/iio/light/gp2ap002.c +++ b/drivers/iio/light/gp2ap002.c @@ -343,6 +343,10 @@ static int gp2ap002_write_event_config(struct iio_dev *indio_dev, int state) { struct gp2ap002 *gp2ap002 = iio_priv(indio_dev); + int ret; + + if (state == gp2ap002->enabled) + return 0; if (state) { /* @@ -350,14 +354,17 @@ static int gp2ap002_write_event_config(struct iio_dev *indio_dev, * already) and reintialize the sensor by using runtime_pm * callbacks. */ - pm_runtime_get_sync(gp2ap002->dev); - gp2ap002->enabled = true; + ret = pm_runtime_resume_and_get(gp2ap002->dev); + if (ret) + return ret; + } else { pm_runtime_mark_last_busy(gp2ap002->dev); pm_runtime_put_autosuspend(gp2ap002->dev); - gp2ap002->enabled = false; } + gp2ap002->enabled = state; + return 0; } -- 2.53.0