From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc Kleine-Budde Subject: [PATCH V3 RESEND] i2c-imx: do not allow interruptions when waiting for I2C to complete Date: Thu, 15 Jul 2010 09:49:11 +0200 Message-ID: <4C3EBD77.2080803@pengutronix.de> References: <4C1F0FC7.60605@pengutronix.de> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig6CFAB867CD6EC3A0D8F2219E" Return-path: In-Reply-To: <4C1F0FC7.60605-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Wolfram Sang , Marc Kleine-Budde List-Id: linux-i2c@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig6CFAB867CD6EC3A0D8F2219E Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable 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 Reviewed-by: Wolfram Sang --- V2: Remove check for "result < 0" as commented by Wolfram Sang. V3: Remove "result" entirely. drivers/i2c/busses/i2c-imx.c | 12 +++--------- 1 files changed, 3 insertions(+), 9 deletions(-) diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c index d1ff940..4c2a62b 100644 --- a/drivers/i2c/busses/i2c-imx.c +++ b/drivers/i2c/busses/i2c-imx.c @@ -159,15 +159,9 @@ static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy) static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx) { - int result; - - result =3D wait_event_interruptible_timeout(i2c_imx->queue, - i2c_imx->i2csr & I2SR_IIF, HZ / 10); + 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 +289,7 @@ static irqreturn_t i2c_imx_isr(int irq, void *dev_id)= i2c_imx->i2csr =3D temp; temp &=3D ~I2SR_IIF; writeb(temp, i2c_imx->base + IMX_I2C_I2SR); - wake_up_interruptible(&i2c_imx->queue); + wake_up(&i2c_imx->queue); return IRQ_HANDLED; } --=20 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-i2c" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html --------------enig6CFAB867CD6EC3A0D8F2219E Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iEYEARECAAYFAkw+vXcACgkQjTAFq1RaXHP/tQCgjGCBzuWUuPm3S6EetU0XGl9L BiAAnjiZosx8kvZhrx9Cmc4Crjym42OJ =xF9n -----END PGP SIGNATURE----- --------------enig6CFAB867CD6EC3A0D8F2219E--