From patchwork Sat Jan 4 10:55:37 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauro Carvalho Chehab X-Patchwork-Id: 3433521 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 0A614C02DD for ; Sat, 4 Jan 2014 13:59:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 2579F20134 for ; Sat, 4 Jan 2014 13:59:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 22B0020136 for ; Sat, 4 Jan 2014 13:59:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754347AbaADN7w (ORCPT ); Sat, 4 Jan 2014 08:59:52 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:43699 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753656AbaADN7T (ORCPT ); Sat, 4 Jan 2014 08:59:19 -0500 Received: from [177.143.150.208] (helo=smtp.w2.samsung.com) by bombadil.infradead.org with esmtpsa (Exim 4.80.1 #2 (Red Hat Linux)) id 1VzRky-00013m-OZ; Sat, 04 Jan 2014 13:59:17 +0000 Received: from mchehab by smtp.w2.samsung.com with local (Exim 4.80.1) (envelope-from ) id 1VzOtV-0003kB-K5; Sat, 04 Jan 2014 08:55:53 -0200 From: Mauro Carvalho Chehab Cc: Mauro Carvalho Chehab , Linux Media Mailing List , Mauro Carvalho Chehab Subject: [PATCH v4 08/22] [media] em28xx: convert i2c wait completion logic to use jiffies Date: Sat, 4 Jan 2014 08:55:37 -0200 Message-Id: <1388832951-11195-9-git-send-email-m.chehab@samsung.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1388832951-11195-1-git-send-email-m.chehab@samsung.com> References: <1388832951-11195-1-git-send-email-m.chehab@samsung.com> To: unlisted-recipients:; (no To-header on input) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Spam-Status: No, score=-7.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The I2C wait completion/timeout logic currently assumes that msleep(5) will wait exaclty 5 ms. This is not true at all, as it depends on CONFIG_HZ. Convert it to use jiffies, in order to not wait for more time than needed. Signed-off-by: Mauro Carvalho Chehab --- drivers/media/usb/em28xx/em28xx-i2c.c | 65 ++++++++++++++++++----------------- 1 file changed, 34 insertions(+), 31 deletions(-) diff --git a/drivers/media/usb/em28xx/em28xx-i2c.c b/drivers/media/usb/em28xx/em28xx-i2c.c index 9e6a11d01858..9fa7ed51e5b1 100644 --- a/drivers/media/usb/em28xx/em28xx-i2c.c +++ b/drivers/media/usb/em28xx/em28xx-i2c.c @@ -26,6 +26,7 @@ #include #include #include +#include #include "em28xx.h" #include "tuner-xc2028.h" @@ -48,8 +49,8 @@ MODULE_PARM_DESC(i2c_debug, "enable debug messages [i2c]"); */ static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len) { + unsigned long timeout = jiffies + msecs_to_jiffies(EM2800_I2C_XFER_TIMEOUT); int ret; - int write_timeout; u8 b2[6]; if (len < 1 || len > 4) @@ -74,15 +75,15 @@ static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len) return (ret < 0) ? ret : -EIO; } /* wait for completion */ - for (write_timeout = EM2800_I2C_XFER_TIMEOUT; write_timeout > 0; - write_timeout -= 5) { + while (time_is_after_jiffies(timeout)) { ret = dev->em28xx_read_reg(dev, 0x05); - if (ret == 0x80 + len - 1) { + if (ret == 0x80 + len - 1) return len; - } else if (ret == 0x94 + len - 1) { + if (ret == 0x94 + len - 1) { em28xx_warn("R05 returned 0x%02x: I2C timeout", ret); return -ENODEV; - } else if (ret < 0) { + } + if (ret < 0) { em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n", ret); return ret; @@ -99,9 +100,9 @@ static int em2800_i2c_send_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len) */ static int em2800_i2c_recv_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len) { + unsigned long timeout = jiffies + msecs_to_jiffies(EM2800_I2C_XFER_TIMEOUT); u8 buf2[4]; int ret; - int read_timeout; int i; if (len < 1 || len > 4) @@ -118,15 +119,15 @@ static int em2800_i2c_recv_bytes(struct em28xx *dev, u8 addr, u8 *buf, u16 len) } /* wait for completion */ - for (read_timeout = EM2800_I2C_XFER_TIMEOUT; read_timeout > 0; - read_timeout -= 5) { + while (time_is_after_jiffies(timeout)) { ret = dev->em28xx_read_reg(dev, 0x05); - if (ret == 0x84 + len - 1) { + if (ret == 0x84 + len - 1) break; - } else if (ret == 0x94 + len - 1) { + if (ret == 0x94 + len - 1) { em28xx_warn("R05 returned 0x%02x: I2C timeout", ret); return -ENODEV; - } else if (ret < 0) { + } + if (ret < 0) { em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n", ret); return ret; @@ -170,7 +171,8 @@ static int em2800_i2c_check_for_device(struct em28xx *dev, u8 addr) static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len, int stop) { - int write_timeout, ret; + unsigned long timeout = jiffies + msecs_to_jiffies(EM2800_I2C_XFER_TIMEOUT); + int ret; if (len < 1 || len > 64) return -EOPNOTSUPP; @@ -193,17 +195,18 @@ static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf, } } - /* Check success of the i2c operation */ - for (write_timeout = EM2800_I2C_XFER_TIMEOUT; write_timeout > 0; - write_timeout -= 5) { + /* wait for completion */ + while (time_is_after_jiffies(timeout)) { ret = dev->em28xx_read_reg(dev, 0x05); - if (ret == 0) { /* success */ + if (ret == 0) /* success */ return len; - } else if (ret == 0x10) { - em28xx_warn("I2C transfer timeout on writing to addr 0x%02x", addr); + if (ret == 0x10) { + em28xx_warn("I2C transfer timeout on writing to addr 0x%02x", + addr); return -ENODEV; - } else if (ret < 0) { - em28xx_warn("failed to read i2c transfer status from bridge (error=%i)\n", + } + if (ret < 0) { + em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n", ret); return ret; } @@ -214,6 +217,7 @@ static int em28xx_i2c_send_bytes(struct em28xx *dev, u16 addr, u8 *buf, * (even with high payload) ... */ } + em28xx_warn("write to i2c device at 0x%x timed out\n", addr); return -EIO; } @@ -251,21 +255,20 @@ static int em28xx_i2c_recv_bytes(struct em28xx *dev, u16 addr, u8 *buf, u16 len) /* Check success of the i2c operation */ ret = dev->em28xx_read_reg(dev, 0x05); + if (ret == 0) /* success */ + return len; if (ret < 0) { - em28xx_warn("failed to read i2c transfer status from bridge (error=%i)\n", + em28xx_warn("failed to get i2c transfer status from bridge register (error=%i)\n", ret); return ret; } - if (ret > 0) { - if (ret == 0x10) { - em28xx_warn("I2C transfer timeout on read from addr 0x%02x", addr); - return -ENODEV; - } else { - em28xx_warn("unknown i2c error (status=%i)\n", ret); - return -EIO; - } + if (ret == 0x10) { + em28xx_warn("I2C transfer timeout on read from addr 0x%02x", addr); + return -ENODEV; } - return len; + + em28xx_warn("unknown i2c error (status=%i)\n", ret); + return -EIO; } /*