From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sonic Zhang Subject: [PATCH 3/8 v2] i2c: i2c-bfin-twi: Break dead waiting loop if i2c device misbehaves. Date: Wed, 13 Jun 2012 16:22:42 +0800 Message-ID: <1339575767-22985-3-git-send-email-sonic.adi@gmail.com> References: <1339575767-22985-1-git-send-email-sonic.adi@gmail.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1339575767-22985-1-git-send-email-sonic.adi@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Wolfram Sang , Ben Dooks Cc: linux-i2c@vger.kernel.org, LKML , uclinux-dist-devel@blackfin.uclinux.org, Sonic Zhang List-Id: linux-i2c@vger.kernel.org From: Sonic Zhang Some fault i2c device may hold the sda/scl line and cause i2c driver wait in the BUS busy loop. The I2C framework already retry the transfer loop before timeout. Return -EAGAIN instead of pull BUSBUSY in the other loop. Signed-off-by: Sonic Zhang --- drivers/i2c/busses/i2c-bfin-twi.c | 8 ++++---- 1 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/i2c/busses/i2c-bfin-twi.c b/drivers/i2c/busses/i2c-bfin-twi.c index dbe8fa0..a5ab454 100644 --- a/drivers/i2c/busses/i2c-bfin-twi.c +++ b/drivers/i2c/busses/i2c-bfin-twi.c @@ -307,8 +307,8 @@ static int bfin_twi_do_master_xfer(struct i2c_adapter *adap, if (!(read_CONTROL(iface) & TWI_ENA)) return -ENXIO; - while (read_MASTER_STAT(iface) & BUSBUSY) - yield(); + if (read_MASTER_STAT(iface) & BUSBUSY) + return -EAGAIN; iface->pmsg = msgs; iface->msg_num = num; @@ -407,8 +407,8 @@ int bfin_twi_do_smbus_xfer(struct i2c_adapter *adap, u16 addr, if (!(read_CONTROL(iface) & TWI_ENA)) return -ENXIO; - while (read_MASTER_STAT(iface) & BUSBUSY) - yield(); + if (read_MASTER_STAT(iface) & BUSBUSY) + return -EAGAIN; iface->writeNum = 0; iface->readNum = 0; -- 1.7.0.4