From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH] ARM: OMAP: Fix occasional i2c driver hang Date: Wed, 10 Sep 2008 16:42:47 -0700 Message-ID: <20080910234246.GR21163@atomide.com> References: <423644ca0808281230g1f8c20ceta4a6822098d4e431@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-01-bos.mailhop.org ([63.208.196.178]:51931 "EHLO mho-01-bos.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752204AbYIJXms (ORCPT ); Wed, 10 Sep 2008 19:42:48 -0400 Content-Disposition: inline In-Reply-To: <423644ca0808281230g1f8c20ceta4a6822098d4e431@mail.gmail.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Jason Marini Cc: linux-omap@vger.kernel.org * Jason Marini [080828 12:31]: > The i2c driver contains a while loop that has no timeout. If i2c is in a > funky state and OMAP_I2C_CON_STT remains asserted, the kernel hangs. Insert > the standard i2c timeout into the loop. Pushing today. Tony > Signed-off-by: Jason P Marini > --- > drivers/i2c/busses/i2c-omap.c | 9 ++++++++- > 1 files changed, 8 insertions(+), 1 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c > index 3c4e581..3a7b6ef 100644 > --- a/drivers/i2c/busses/i2c-omap.c > +++ b/drivers/i2c/busses/i2c-omap.c > @@ -440,9 +440,16 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap, > omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w); > > if (dev->b_hw && stop) { > + unsigned long delay = jiffies + OMAP_I2C_TIMEOUT; > + > /* H/w behavior: dont write stt and stp together.. */ > while (omap_i2c_read_reg(dev, OMAP_I2C_CON_REG) & OMAP_I2C_CON_STT) { > - /* Dont do anything - this will come in a couple of loops at max*/ > + /* Let the user know if i2c is in a bad state */ > + if (time_after (jiffies, delay)) { > + dev_err(dev->dev, "controller timed out " > + "waiting for start condition to finish\n"); > + return -ETIMEDOUT; > + } > } > w |= OMAP_I2C_CON_STP; > w &= ~OMAP_I2C_CON_STT; > -- > 1.5.5.1 > -- > To unsubscribe from this list: send the line "unsubscribe linux-omap" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html