From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: [PATCH] I2C: Fix twl4030 timeouts on omap3430 Date: Fri, 28 Mar 2008 13:46:39 +0200 Message-ID: <1206704800-6768-5-git-send-email-tony@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> Return-path: Received: from mho-01-bos.mailhop.org ([63.208.196.178]:64627 "EHLO mho-01-bos.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753752AbYC1Lqz (ORCPT ); Fri, 28 Mar 2008 07:46:55 -0400 In-Reply-To: <1206704800-6768-4-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 Cc: Tony Lindgren 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. 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; }