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 02005338911; Fri, 9 Jan 2026 12:07:23 +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=1767960443; cv=none; b=b2fmYFrW7KvWcutiprbBptDgGe6PgZlT7y72vzQuw2P3UuV6g2KUonWKnYCg/7s6pMiThSC4nrM5iooVlYUU+xJZ+59yUzg87J5XlJCIg0sbFSiway4a9vBw0KR3zlgOUATCd4I3Offw7WW82bW+t5IPiZAG/qI5o+kcroPh8vg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767960443; c=relaxed/simple; bh=vhyoZ6PJFu6oxfZnxH4bwcPculY6V79HLRNMkxhO8fk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=UYgmtmJ9W3x8nHFpLCqhv54JlrwniEQ8TPM/0slLq5Wd121yof0WIBns+FAjvvgJ5lRNlsGwiEtHAl2K2qRM5BvVy+JM7srqQEUgUsq8a+JOkm6ay45Qn53GbM6FWiIwtBoSsVN8yR2wllZRaTANt7ChSMapORhOc+SKiM1wO5M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=WzGwFZ6l; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="WzGwFZ6l" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 68550C4CEF1; Fri, 9 Jan 2026 12:07:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1767960442; bh=vhyoZ6PJFu6oxfZnxH4bwcPculY6V79HLRNMkxhO8fk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WzGwFZ6lZS1jlYWNJjwUzgeB5yCAXmW/2RyPNz2OF4hqbOMDugsdCIzfOa+DtkyoE nTTsxzO9YHltisURuesAmD1/gKIbCGC88cOhW5Tn8miZ5x56jTbGybDPrEhPoVTgX7 wxmFZTaG90o/hH9vOHEJE8KiomtpAADnNBQ9+hJY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jinhui Guo , Andy Shevchenko , Mika Westerberg , Andi Shyti , Sasha Levin Subject: [PATCH 6.6 406/737] i2c: designware: Disable SMBus interrupts to prevent storms from mis-configured firmware Date: Fri, 9 Jan 2026 12:39:05 +0100 Message-ID: <20260109112149.272432413@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260109112133.973195406@linuxfoundation.org> References: <20260109112133.973195406@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jinhui Guo [ Upstream commit d3429178ee51dd7155445d15a5ab87a45fae3c73 ] When probing the I2C master, disable SMBus interrupts to prevent storms caused by broken firmware mis-configuring IC_SMBUS=1; the handler never services them and a mis-configured SMBUS Master extend-clock timeout or SMBUS Slave extend-clock timeout can flood the CPU. Signed-off-by: Jinhui Guo Reviewed-by: Andy Shevchenko Acked-by: Mika Westerberg Signed-off-by: Andi Shyti Link: https://lore.kernel.org/r/20251021075714.3712-2-guojinhui.liam@bytedance.com Signed-off-by: Sasha Levin --- drivers/i2c/busses/i2c-designware-core.h | 1 + drivers/i2c/busses/i2c-designware-master.c | 7 +++++++ 2 files changed, 8 insertions(+) diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h index e93870a0f9a4..f8feae20a7b2 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -79,6 +79,7 @@ #define DW_IC_TX_ABRT_SOURCE 0x80 #define DW_IC_ENABLE_STATUS 0x9c #define DW_IC_CLR_RESTART_DET 0xa8 +#define DW_IC_SMBUS_INTR_MASK 0xcc #define DW_IC_COMP_PARAM_1 0xf4 #define DW_IC_COMP_VERSION 0xf8 #define DW_IC_SDA_HOLD_MIN_VERS 0x3131312A /* "111*" == v1.11* */ diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c index e865869ccc50..56f124f32cac 100644 --- a/drivers/i2c/busses/i2c-designware-master.c +++ b/drivers/i2c/busses/i2c-designware-master.c @@ -184,6 +184,13 @@ static int i2c_dw_init_master(struct dw_i2c_dev *dev) /* Disable the adapter */ __i2c_dw_disable(dev); + /* + * Mask SMBus interrupts to block storms from broken + * firmware that leaves IC_SMBUS=1; the handler never + * services them. + */ + regmap_write(dev->map, DW_IC_SMBUS_INTR_MASK, 0); + /* Write standard speed timing parameters */ regmap_write(dev->map, DW_IC_SS_SCL_HCNT, dev->ss_hcnt); regmap_write(dev->map, DW_IC_SS_SCL_LCNT, dev->ss_lcnt); -- 2.51.0