From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f176.google.com (mail-pl1-f176.google.com [209.85.214.176]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C02F0503BED for ; Thu, 3 Sep 2026 19:31:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.176 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788463897; cv=none; b=KUSZl3/DrJ2AhrG2zo5wHPAVDuK0kI462oyIVS56bjnPsFzF9EleHChoRPXThUK4436jnIPFQJPtf9BgnsAgGB4xr6omZzdZtJJdkAv3u+p0gcwSFElbJeZprdYzh7xmmZYBFE8e/66nxnBS0Bvb80Bfl435AzCU2ak39CGdOQw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788463897; c=relaxed/simple; bh=LRIB+Ien8LNhu1QGXr1xo2szN3dRaFD/6agQW0q8qxs=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=THeZWPsi6zXOVBGOHC4oXL2FnGpl9Fat2t8bDWxu03G2nvwraMwyAuY438QRzddYTRzfB94Vd2ETUWo/2zT8K6UpmXTa3E2EBFjMvy9osGkkpx2QwEtBJxsKfl6eE/X/zh1IDAgrUjOwocymmBQEEXobYCJtTHGw66bFzy9j8eM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Rwdqi28I; arc=none smtp.client-ip=209.85.214.176 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Rwdqi28I" Received: by mail-pl1-f176.google.com with SMTP id d9443c01a7336-2cc891373e0so2035585ad.2 for ; Thu, 03 Sep 2026 12:31:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1788463872; x=1789068672; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=4yIetKXnfU6qQx5OfRzSQNhmvwvEsmpVmmGdbC2BbsE=; b=Rwdqi28IC2n6hedfuQzzuOvAxUHwIrsve3Gvv5hDjjOH8/BdTlPKNocnWSsZ9iHz24 Cf+BJGD6z+rNWWJZ5WlUG9TeDcubItwYFJro72JonhFc1nnLyjJ/F9dSmhevIr6UQnIA wJshvg0BFGbf+Y5fSBSkZgfoHksoPLpFYdAYUWKh6V88P39NLoeLhRb+8kJiBMm3cEXr 8q/hpredYakkLfqPSedRw2qfHjPHFjAAkwid8sfU4XUlCpGtOl5Fh/FcBVsVcoHPOEET bAuvGHb7GsC34+irRuoncZwGEQ5dvd4T206H1kllv9+yTopMbixMwhS5d+WNqOhPsrOb uhFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1788463872; x=1789068672; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=4yIetKXnfU6qQx5OfRzSQNhmvwvEsmpVmmGdbC2BbsE=; b=WDs5ySBhiKhFeduQa/VTpCFA04fCBAzScvmeGWK7SbVO2ZeTnJdcbUA/xsSIsHfq/e NgagW9QLLcIDNl4TUu/KWKwsRvWBYCFAOoRILR/s52PyiEVXAHibGpcv9dG762wQXO9s Xwq2jJKVM8Ol1pt38p9UWzZU3PFrgCXq39Htiv1fYdml4ckH9sCuprnX/UbnW65oXr0w trs6Xn6c7eBoxlKwKGo6VNTlB2G+gsEiE7ymJ446iREIYBvUdemP7qlOlGn2wCUd6G3d Wt+0uuKbp7ZOep7jreDIB4+uX+/75Ud3IFuoju9cGBcW/RlOX11MpiXv4wVSt7+moZzF 0WrA== X-Forwarded-Encrypted: i=1; AKwUvByU1m85p0zfUKm4vqlEaAqdZHnVF12mm03ut1VUbv5o873XeRI9r209hjAf1gNk/V4VDnDAqSc=@vger.kernel.org X-Gm-Message-State: AFuF++m4Zkxm5XpobUCb2BJ/dDN3ybD5Hg2F5TJeEFNZ57V69w1sGIde 5k4URmnMJ1UJhtkEPjUW1SmGIsuRX2gCTbTjG+a2W0kW1CbLYTpW6buo X-Gm-Gg: AYBFou2xUPy3MNazZ+papCao7Pyo0vnAh1/vEdgZsZ5WviWZtWmA0qMXtpyovNSDEyn IzDlyMqV/yUwW43bmrPtjvoyYpjokWOsbb0z5dsmY/VXF6B//lS8j8LaHqriY3klXjum7tPoHXK 3NVvegKGNU3B+72w+D+a7tSnpiXJlCy36aDTWKurV7PAGt2y+wUMUfsnZI49CVqLsSlOL0Z72eP tiPL+N1IIBWHDqPjXUIvXINqlorVAGTGvzZHf5A/0BaKaAX3CmRh//p0C/KR+6rCMsGQE2WayPV xgPFKvo2vYrF18OpSEWof78a+bMmtFRL6VXuJQiCw7JvK0fWTnDP4X2NUaavhGl8F1wf4hx4nen yNX6eHU7+ldF48vRv+WncDq7/D9aP9CJ1+01LveQhjJMHRWzxlL+OFyP4EW9HWh4Ea/Y9g9afeD lw6Rx+/KH24i/xx8/9KDJdhB1MzwqAuWsa5uooHAxd7PXYkRoGkAx8YMeVbaCovFGPLY+4N3HYc 8jTyJybYiDsfNAGGZrcjz2S4VxazIcdbReNIb+z7dszRQ== X-Received: by 2002:a17:903:1670:b0:2d9:438e:b70d with SMTP id d9443c01a7336-2db1232c88emr19260755ad.1.1788463872345; Thu, 03 Sep 2026 12:31:12 -0700 (PDT) Received: from lza-virtual-machine.localdomain ([223.160.226.115]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2db14ae53ddsm396985ad.78.2026.09.03.12.31.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Sep 2026 12:31:12 -0700 (PDT) From: Zhian Liang To: Dmitry Torokhov Cc: linux-input@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Zhian Liang Subject: [PATCH 2/2] Input: tca8418_keypad - fix race condition in interrupt handler Date: Fri, 4 Sep 2026 03:29:42 +0800 Message-Id: <20260903192942.21906-2-liangzhan5dev@gmail.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20260903192942.21906-1-liangzhan5dev@gmail.com> References: <20260903192942.21906-1-liangzhan5dev@gmail.com> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit There is a race condition in tca8418_irq_handler() where a new key event can be lost if it arrives after the FIFO is drained but before the interrupt status register is cleared. Fix this by re-reading INT_STAT after draining the FIFO and repeating the process if K_INT is still asserted. This ensures the FIFO is truly empty before clearing interrupts. The FIFO depth is 10 events, so a loop limit of 16 provides sufficient margin while preventing infinite loops in case of hardware misbehavior. Signed-off-by: Zhian Liang --- drivers/input/keyboard/tca8418_keypad.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/input/keyboard/tca8418_keypad.c b/drivers/input/keyboard/tca8418_keypad.c index 9f0aace6bd21..0952370c0636 100644 --- a/drivers/input/keyboard/tca8418_keypad.c +++ b/drivers/input/keyboard/tca8418_keypad.c @@ -212,6 +212,7 @@ static irqreturn_t tca8418_irq_handler(int irq, void *dev_id) struct tca8418_keypad *keypad_data = dev_id; u8 reg; int error; + int max_loops = 16; error = tca8418_read_byte(keypad_data, REG_INT_STAT, ®); if (error) { @@ -225,9 +226,19 @@ static irqreturn_t tca8418_irq_handler(int irq, void *dev_id) if (reg & INT_STAT_OVR_FLOW_INT) dev_warn(&keypad_data->client->dev, "overflow occurred\n"); + do { + if (reg & INT_STAT_K_INT) + tca8418_read_keypad(keypad_data); + + /* Re-read interrupt status to check for new events */ + error = tca8418_read_byte(keypad_data, REG_INT_STAT, ®); + if (error) { + dev_err(&keypad_data->client->dev, + "unable to re-read REG_INT_STAT\n"); + return IRQ_HANDLED; + } - if (reg & INT_STAT_K_INT) - tca8418_read_keypad(keypad_data); + } while ((reg & INT_STAT_K_INT) && --max_loops); /* Clear all interrupts, even IRQs we didn't check (GPI, CAD, LCK) */ reg = 0xff; -- 2.34.1