From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [PATCH] I2C: Fix twl4030 timeouts on omap3430 Date: Fri, 28 Mar 2008 13:48:59 +0200 Message-ID: <20080328114858.GD24896@atomide.com> References: <1206704800-6768-1-git-send-email-tony@atomide.com> <1206704800-6768-2-git-send-email-tony@atomide.com> <1206704800-6768-3-git-send-email-tony@atomide.com> <1206704800-6768-4-git-send-email-tony@atomide.com> <1206704800-6768-5-git-send-email-tony@atomide.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]:51682 "EHLO mho-01-bos.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752483AbYC1LtA (ORCPT ); Fri, 28 Mar 2008 07:49:00 -0400 Received: from muru.com ([72.249.23.125] helo=localhost.localdomain) by mho-01-bos.mailhop.org with esmtpa (Exim 4.68) (envelope-from ) id 1JfD4t-000HvZ-JO for linux-omap@vger.kernel.org; Fri, 28 Mar 2008 11:48:59 +0000 Content-Disposition: inline In-Reply-To: <1206704800-6768-5-git-send-email-tony@atomide.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: linux-omap@vger.kernel.org * Tony Lindgren [080328 13:47]: > For some reason doing a twl4030 write-read cycle can hang the I2C bus > on omap3430. And doing the write and read separately in twl4030_i2c_read() > seems to fix the problem... > > Not intended for applying, just a temporary workaround. Uh, please ignore this one, git-send-email weirdness where it sends all files ending in .patch.. The series should only contain two patches. Tony > > diff --git a/drivers/i2c/chips/twl4030-core.c b/drivers/i2c/chips/twl4030-core.c > index ded86e7..62868b0 100644 > --- a/drivers/i2c/chips/twl4030-core.c > +++ b/drivers/i2c/chips/twl4030-core.c > @@ -327,6 +327,7 @@ int twl4030_i2c_read(u8 mod_no, u8 * value, u8 reg, u8 num_bytes) > return -EPERM; > } > mutex_lock(&twl->xfer_lock); > + > /* [MSG1] fill the register address data */ > msg = &twl->xfer_msg[0]; > msg->addr = twl->address; > @@ -334,18 +335,25 @@ int twl4030_i2c_read(u8 mod_no, u8 * value, u8 reg, u8 num_bytes) > msg->flags = 0; /* Read the register value */ > val = twl4030_map[mod_no].base + reg; > msg->buf = &val; > + ret = i2c_transfer(twl->client.adapter, twl->xfer_msg, 1); > + if (ret < 0) > + goto out; > + > /* [MSG2] fill the data rx buffer */ > msg = &twl->xfer_msg[1]; > msg->addr = twl->address; > msg->flags = I2C_M_RD; /* Read the register value */ > msg->len = num_bytes; /* only n bytes */ > msg->buf = value; > - ret = i2c_transfer(twl->client.adapter, twl->xfer_msg, 2); > + ret = i2c_transfer(twl->client.adapter, twl->xfer_msg, 1); > + > +out: > mutex_unlock(&twl->xfer_lock); > > /* i2cTransfer returns num messages.translate it pls.. */ > if (ret >= 0) > ret = 0; > + > return ret; > } >