linux-kernel - [PATCH v2 08/10] media: tda18271: switch to i2c_lock_bus(..., I2C_LOCK

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20180620051803.12206-9-peda@axentia.se>
Date:   Wed, 20 Jun 2018 07:18:01 +0200
From:   Peter Rosin <peda@...ntia.se>
To:     linux-kernel@...r.kernel.org
Cc:     Peter Rosin <peda@...ntia.se>, Peter Huewe <peterhuewe@....de>,
        Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>,
        Jason Gunthorpe <jgg@...pe.ca>, Arnd Bergmann <arnd@...db.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Brian Norris <computersforpeace@...il.com>,
        Gregory Fong <gregory.0xf0@...il.com>,
        Florian Fainelli <f.fainelli@...il.com>,
        bcm-kernel-feedback-list@...adcom.com,
        Sekhar Nori <nsekhar@...com>,
        Kevin Hilman <khilman@...nel.org>,
        Haavard Skinnemoen <hskinnemoen@...il.com>,
        Kukjin Kim <kgene@...nel.org>,
        Krzysztof Kozlowski <krzk@...nel.org>,
        Orson Zhai <orsonzhai@...il.com>,
        Baolin Wang <baolin.wang@...aro.org>,
        Chunyan Zhang <zhang.lyra@...il.com>,
        Wolfram Sang <wsa@...-dreams.de>,
        Guenter Roeck <linux@...ck-us.net>, Crt Mori <cmo@...exis.com>,
        Jonathan Cameron <jic23@...nel.org>,
        Hartmut Knaack <knaack.h@....de>,
        Lars-Peter Clausen <lars@...afoo.de>,
        Peter Meerwald-Stadler <pmeerw@...erw.net>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Antti Palosaari <crope@....fi>,
        Mauro Carvalho Chehab <mchehab@...nel.org>,
        Michael Krufky <mkrufky@...uxtv.org>,
        Lee Jones <lee.jones@...aro.org>,
        linux-integrity@...r.kernel.org, linux-i2c@...r.kernel.org,
        linux-arm-kernel@...ts.infradead.org,
        linux-samsung-soc@...r.kernel.org, linux-iio@...r.kernel.org,
        linux-input@...r.kernel.org, linux-media@...r.kernel.org
Subject: [PATCH v2 08/10] media: tda18271: switch to i2c_lock_bus(..., I2C_LOCK_SEGMENT)

Locking the root adapter for __i2c_transfer will deadlock if the
device sits behind a mux-locked I2C mux. Switch to the finer-grained
i2c_lock_bus with the I2C_LOCK_SEGMENT flag. If the device does not
sit behind a mux-locked mux, the two locking variants are equivalent.

Signed-off-by: Peter Rosin <peda@...ntia.se>
---
 drivers/media/tuners/tda18271-common.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/media/tuners/tda18271-common.c b/drivers/media/tuners/tda18271-common.c
index 7e81cd887c13..054b3b747dae 100644
--- a/drivers/media/tuners/tda18271-common.c
+++ b/drivers/media/tuners/tda18271-common.c
@@ -225,7 +225,7 @@ static int __tda18271_write_regs(struct dvb_frontend *fe, int idx, int len,
 	 */
 	if (lock_i2c) {
 		tda18271_i2c_gate_ctrl(fe, 1);
-		i2c_lock_adapter(priv->i2c_props.adap);
+		i2c_lock_bus(priv->i2c_props.adap, I2C_LOCK_SEGMENT);
 	}
 	while (len) {
 		if (max > len)
@@ -246,7 +246,7 @@ static int __tda18271_write_regs(struct dvb_frontend *fe, int idx, int len,
 		len -= max;
 	}
 	if (lock_i2c) {
-		i2c_unlock_adapter(priv->i2c_props.adap);
+		i2c_unlock_bus(priv->i2c_props.adap, I2C_LOCK_SEGMENT);
 		tda18271_i2c_gate_ctrl(fe, 0);
 	}
 
@@ -300,7 +300,7 @@ int tda18271_init_regs(struct dvb_frontend *fe)
 	 * as those could cause bad things
 	 */
 	tda18271_i2c_gate_ctrl(fe, 1);
-	i2c_lock_adapter(priv->i2c_props.adap);
+	i2c_lock_bus(priv->i2c_props.adap, I2C_LOCK_SEGMENT);
 
 	/* initialize registers */
 	switch (priv->id) {
@@ -516,7 +516,7 @@ int tda18271_init_regs(struct dvb_frontend *fe)
 	/* synchronize */
 	__tda18271_write_regs(fe, R_EP1, 1, false);
 
-	i2c_unlock_adapter(priv->i2c_props.adap);
+	i2c_unlock_bus(priv->i2c_props.adap, I2C_LOCK_SEGMENT);
 	tda18271_i2c_gate_ctrl(fe, 0);
 
 	return 0;
-- 
2.11.0