From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 C2AB4257AF3; Sun, 1 Jun 2025 23:34:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748820874; cv=none; b=ix0eeFjythJm0Wusq2THTQipgtA8LOoVkcCrbvzgQFrqZJ78R9I7kQ/8spU4fJ5nZpeAVkwvi6IKG9mf1fIbZZzCXLRWNvjmetNkk6ZHI3S19lFoCNeMuDsTqk/zNtwY4Wi5HLo08S1nRgoqatUwdY4ZUW1velHx1kckYPE/L7Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748820874; c=relaxed/simple; bh=f2WYD4Y4R0bJMxER0HxNBbKZ+Ld3JpjNmYLQli+y9PI=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=aBNBk1/TS4sJboOLxrhrkPc4bYJFPnEJvePmHU0pvDQOq5/1+Spyx909soqMZney28ROilhC8wEje6PPhDqSTuvy2trKbm9/iFX7r3HhsA0YvHBKZqLkaGPhhxALJliJa3crnIKM+PgjI6SeEkq5gbKFMMC11pKM+RPgu6tTeZo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=KoJIq2Ez; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="KoJIq2Ez" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5C84CC4CEE7; Sun, 1 Jun 2025 23:34:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1748820874; bh=f2WYD4Y4R0bJMxER0HxNBbKZ+Ld3JpjNmYLQli+y9PI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KoJIq2Ezbe35o2ltQlb4aQm79qR/eM0uG5SgHQp7gHfPUrHOqrMhUYIk0uvofXP/J dadEYVrM5fyjKOeFocctOQtfdLzUcAMJ5vMkPFB3LNHE68wt2SdSjIUvgNlLrcbPSk oYMwi3lEaKGBh1zrTUkSjo4dZrCfwmHutCStAwXACc224hp43nD8C+Az7Qcbc3ZiwC yBUdsK6BAEQvGjRwUoaL1NaL5KiG/I7+ihMBuEKxvAWd3oIzb1Z+lUfHFH7tvakeWP ZiIaagYVh/MpiQKe5dqr+KrhPf31OBqhrWQ9HIX2104CzOozZrZ5LxOozK3SZ+0EYj z/YCN5Eqc00sQ== From: Sasha Levin To: patches@lists.linux.dev, stable@vger.kernel.org Cc: Damon Ding , Douglas Anderson , Dmitry Baryshkov , Sasha Levin , andrzej.hajda@intel.com, neil.armstrong@linaro.org, rfoss@kernel.org, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, airlied@gmail.com, simona@ffwll.ch, l.stach@pengutronix.de, bivvy.bi@rock-chips.com, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: [PATCH AUTOSEL 6.12 10/93] drm/bridge: analogix_dp: Add irq flag IRQF_NO_AUTOEN instead of calling disable_irq() Date: Sun, 1 Jun 2025 19:32:37 -0400 Message-Id: <20250601233402.3512823-10-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250601233402.3512823-1-sashal@kernel.org> References: <20250601233402.3512823-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.12.31 Content-Transfer-Encoding: 8bit From: Damon Ding [ Upstream commit efab13e7d13a641a22c7508cde6e1a5285161944 ] The IRQF_NO_AUTOEN can be used for the drivers that don't want interrupts to be enabled automatically via devm_request_threaded_irq(). Using this flag can provide be more robust compared to the way of calling disable_irq() after devm_request_threaded_irq() without the IRQF_NO_AUTOEN flag. Suggested-by: Douglas Anderson Reviewed-by: Douglas Anderson Signed-off-by: Damon Ding Link: https://lore.kernel.org/r/20250310104114.2608063-2-damon.ding@rock-chips.com Signed-off-by: Dmitry Baryshkov Signed-off-by: Sasha Levin --- **YES** This commit should be backported to stable kernel trees based on the following analysis: ## Code Change Analysis The commit makes a simple, targeted fix to address a race condition in interrupt handling: 1. **Line 1639**: Changes `irq_flags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING;` to `irq_flags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_NO_AUTOEN;` 2. **Line 1642**: Changes `irq_flags = 0;` to `irq_flags = IRQF_NO_AUTOEN;` 3. **Line 1659**: Removes the `disable_irq(dp->irq);` call that was previously needed after `devm_request_threaded_irq()` ## Backport Suitability Assessment **Matches Stable Tree Criteria:** 1. **Fixes an Important Bug**: The commit addresses a race condition where interrupts can fire between `devm_request_threaded_irq()` and `disable_irq()`, which could cause system instability or unexpected behavior. 2. **Small and Contained Change**: The modification is minimal (3 lines changed) and affects only the interrupt setup logic in `analogix_dp_core.c:1608-1659`. 3. **Low Risk of Regression**: The change uses a well-established kernel pattern (IRQF_NO_AUTOEN) that's been proven safe across multiple subsystems. 4. **Clear Technical Merit**: As noted in the commit message, using `IRQF_NO_AUTOEN` is "more robust compared to the way of calling disable_irq() after devm_request_threaded_irq()". **Strong Precedent from Similar Commits:** The analysis shows **ALL** similar commits in the provided reference set have "Backport Status: YES": - `drm/msm/adreno: Use IRQF_NO_AUTOEN flag in request_irq()` - **YES** - `drm/imx/dcss: Use IRQF_NO_AUTOEN flag in request_irq()` (both instances) - **YES** - `drm/imx/ipuv3: Use IRQF_NO_AUTOEN flag in request_irq()` - **YES** - `drm/exynos: move to use request_irq by IRQF_NO_AUTOEN flag` - **YES** **Additional Context from Kernel Repository:** Examination of `/home/sasha/linux/drivers/gpu/drm/bridge/a nalogix/analogix_dp_core.c:1659` confirms this follows the exact same pattern as other successful backports - replacing the `request_irq()` + `disable_irq()` sequence with `IRQF_NO_AUTOEN` flag usage. This is a textbook example of a stable tree candidate: it fixes a real race condition bug with minimal, proven-safe code changes that follow established kernel patterns. drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c index bfa88409a7ff0..e23af674d91c0 100644 --- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c +++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c @@ -1636,10 +1636,10 @@ analogix_dp_probe(struct device *dev, struct analogix_dp_plat_data *plat_data) * that we can get the current state of the GPIO. */ dp->irq = gpiod_to_irq(dp->hpd_gpiod); - irq_flags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING; + irq_flags = IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING | IRQF_NO_AUTOEN; } else { dp->irq = platform_get_irq(pdev, 0); - irq_flags = 0; + irq_flags = IRQF_NO_AUTOEN; } if (dp->irq == -ENXIO) { @@ -1656,7 +1656,6 @@ analogix_dp_probe(struct device *dev, struct analogix_dp_plat_data *plat_data) dev_err(&pdev->dev, "failed to request irq\n"); goto err_disable_clk; } - disable_irq(dp->irq); return dp; -- 2.39.5