From: Marc Kleine-Budde <mkl@pengutronix.de> To: "Ben Dooks (embedded platforms)" <ben-linux@fluff.org> Cc: Marc Kleine-Budde <mkl@pengutronix.de>, Sascha Hauer <sha@pengutronix.de>, linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH V2] i2c-imx: do not allow interruptions when waiting for I2C to complete (resend) Date: Tue, 15 Jun 2010 12:20:38 +0200 [thread overview] Message-ID: <4C1753F6.3080106@pengutronix.de> (raw) [-- Attachment #1: Type: text/plain, Size: 1969 bytes --] The i2c_imx_trx_complete() function is using wait_event_interruptible_timeout() to wait for the I2C controller to signal that it has completed an I2C bus operation. If the process that causes the I2C operation receives a signal, the wait will be interrupted, returning an error. It is better to let the I2C operation finished before handling the signal (i.e. returning into userspace). It is safe to use wait_event_timeout() instead, because the timeout will allow the process to exit if the I2C bus hangs. It's also better to allow the I2C operation to finish, because unacknowledged I2C operations can cause the I2C bus to hang. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Reviewed-by: Wolfram Sang <w.sang@pengutronix.de> --- V2: Remove check for "result < 0" as commented by Wolfram Sang. drivers/i2c/busses/i2c-imx.c | 9 +++------ 1 files changed, 3 insertions(+), 6 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index d1ff940..58df809 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -161,13 +161,10 @@ static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx) { int result; - result = wait_event_interruptible_timeout(i2c_imx->queue, + result = wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10); - if (unlikely(result < 0)) { - dev_dbg(&i2c_imx->adapter.dev, "<%s> result < 0\n", __func__); - return result; - } else if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) { + if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) { dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__); return -ETIMEDOUT; } @@ -295,7 +292,7 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id) i2c_imx->i2csr = temp; temp &= ~I2SR_IIF; writeb(temp, i2c_imx->base + IMX_I2C_I2SR); - wake_up_interruptible(&i2c_imx->queue); + wake_up(&i2c_imx->queue); return IRQ_HANDLED; } -- 1.7.1 [-- Attachment #2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 260 bytes --]
WARNING: multiple messages have this Message-ID (diff)
From: Marc Kleine-Budde <mkl-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> To: "Ben Dooks (embedded platforms)" <ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org> Cc: Marc Kleine-Budde <mkl-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>, Sascha Hauer <sha-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Subject: [PATCH V2] i2c-imx: do not allow interruptions when waiting for I2C to complete (resend) Date: Tue, 15 Jun 2010 12:20:38 +0200 [thread overview] Message-ID: <4C1753F6.3080106@pengutronix.de> (raw) [-- Attachment #1: Type: text/plain, Size: 2019 bytes --] The i2c_imx_trx_complete() function is using wait_event_interruptible_timeout() to wait for the I2C controller to signal that it has completed an I2C bus operation. If the process that causes the I2C operation receives a signal, the wait will be interrupted, returning an error. It is better to let the I2C operation finished before handling the signal (i.e. returning into userspace). It is safe to use wait_event_timeout() instead, because the timeout will allow the process to exit if the I2C bus hangs. It's also better to allow the I2C operation to finish, because unacknowledged I2C operations can cause the I2C bus to hang. Signed-off-by: Marc Kleine-Budde <mkl-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> Reviewed-by: Wolfram Sang <w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> --- V2: Remove check for "result < 0" as commented by Wolfram Sang. drivers/i2c/busses/i2c-imx.c | 9 +++------ 1 files changed, 3 insertions(+), 6 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index d1ff940..58df809 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -161,13 +161,10 @@ static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx) { int result; - result = wait_event_interruptible_timeout(i2c_imx->queue, + result = wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10); - if (unlikely(result < 0)) { - dev_dbg(&i2c_imx->adapter.dev, "<%s> result < 0\n", __func__); - return result; - } else if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) { + if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) { dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__); return -ETIMEDOUT; } @@ -295,7 +292,7 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id) i2c_imx->i2csr = temp; temp &= ~I2SR_IIF; writeb(temp, i2c_imx->base + IMX_I2C_I2SR); - wake_up_interruptible(&i2c_imx->queue); + wake_up(&i2c_imx->queue); return IRQ_HANDLED; } -- 1.7.1 [-- Attachment #2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 260 bytes --]
next reply other threads:[~2010-06-15 10:20 UTC|newest] Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top 2010-06-15 10:20 Marc Kleine-Budde [this message] 2010-06-15 10:20 ` [PATCH V2] i2c-imx: do not allow interruptions when waiting for I2C to complete (resend) Marc Kleine-Budde 2010-06-20 22:33 ` Ben Dooks 2010-06-21 7:07 ` Marc Kleine-Budde 2010-06-21 7:07 ` Marc Kleine-Budde [not found] ` <4C1F0FC7.60605-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> 2010-06-21 7:27 ` [PATCH V3] i2c-imx: do not allow interruptions when waiting for I2C to complete Marc Kleine-Budde 2010-07-15 7:49 ` [PATCH V3 RESEND] " Marc Kleine-Budde 2010-07-19 8:11 ` [PATCH V3 RESEND2] " Marc Kleine-Budde 2010-09-15 11:45 ` [PATCH V3 RESEND3] " Marc Kleine-Budde 2010-09-24 14:50 ` [PATCH V3 RESEND4] " Marc Kleine-Budde [not found] ` <4C9CBAA1.5040202-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> 2010-09-28 9:05 ` Wolfram Sang 2010-10-04 14:22 ` [PATCH V3 RESEND5] " Marc Kleine-Budde
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