From patchwork Sat Jan 25 17:14:45 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jean-Francois Moine X-Patchwork-Id: 3538221 Return-Path: X-Original-To: patchwork-dri-devel@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 87127C02DC for ; Sat, 25 Jan 2014 17:19:19 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 92014201BB for ; Sat, 25 Jan 2014 17:19:18 +0000 (UTC) Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) by mail.kernel.org (Postfix) with ESMTP id D8F0420109 for ; Sat, 25 Jan 2014 17:19:13 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B5056FA9BC for ; Sat, 25 Jan 2014 09:19:13 -0800 (PST) X-Original-To: dri-devel@lists.freedesktop.org Delivered-To: dri-devel@lists.freedesktop.org Received: from smtp3-g21.free.fr (smtp3-g21.free.fr [212.27.42.3]) by gabe.freedesktop.org (Postfix) with ESMTP id F0BF9FA960 for ; Sat, 25 Jan 2014 09:18:51 -0800 (PST) Received: from armhf (unknown [IPv6:2a01:e35:2f5c:9de0:212:bfff:fe1e:9ce4]) by smtp3-g21.free.fr (Postfix) with ESMTP id 0C6B8A6272; Sat, 25 Jan 2014 18:18:38 +0100 (CET) Date: Sat, 25 Jan 2014 18:14:45 +0100 From: Jean-Francois Moine To: dri-devel@lists.freedesktop.org Subject: [PATCH v4 02/24] drm/i2c: tda998x: check more I/O errors Message-ID: <20140125181445.38f8b30b@armhf> In-Reply-To: References: X-Mailer: Claws Mail 3.9.3 (GTK+ 2.24.22; arm-unknown-linux-gnueabihf) MIME-Version: 1.0 Cc: Russell King - ARM Linux , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.13 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dri-devel-bounces+patchwork-dri-devel=patchwork.kernel.org@lists.freedesktop.org Errors-To: dri-devel-bounces+patchwork-dri-devel=patchwork.kernel.org@lists.freedesktop.org X-Spam-Status: No, score=-4.7 required=5.0 tests=BAYES_00,FREEMAIL_FROM, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable 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 This patch adds more error checking inn I2C I/O functions. In case of I/O error, this permits to avoid writing in bad controller pages, a bad chipset detection or looping when getting the EDID. Acked-by: Russell King Tested-by: Russell King Signed-off-by: Jean-Francois Moine --- drivers/gpu/drm/i2c/tda998x_drv.c | 57 +++++++++++++++++++++++++++++---------- 1 file changed, 43 insertions(+), 14 deletions(-) diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c index 26dd299..11f0607 100644 --- a/drivers/gpu/drm/i2c/tda998x_drv.c +++ b/drivers/gpu/drm/i2c/tda998x_drv.c @@ -362,7 +362,7 @@ fail: return 0; } -static void +static int set_page(struct tda998x_priv *priv, uint16_t reg) { if (REG2PAGE(reg) != priv->current_page) { @@ -371,11 +371,14 @@ set_page(struct tda998x_priv *priv, uint16_t reg) REG_CURPAGE, REG2PAGE(reg) }; int ret = i2c_master_send(client, buf, sizeof(buf)); - if (ret < 0) + if (ret < 0) { dev_err(&client->dev, "Error %d writing to REG_CURPAGE\n", ret); + return ret; + } priv->current_page = REG2PAGE(reg); } + return 0; } static int @@ -385,7 +388,9 @@ reg_read_range(struct tda998x_priv *priv, uint16_t reg, char *buf, int cnt) uint8_t addr = REG2ADDR(reg); int ret; - set_page(priv, reg); + ret = set_page(priv, reg); + if (ret < 0) + return ret; ret = i2c_master_send(client, &addr, sizeof(addr)); if (ret < 0) @@ -412,18 +417,24 @@ reg_write_range(struct tda998x_priv *priv, uint16_t reg, uint8_t *p, int cnt) buf[0] = REG2ADDR(reg); memcpy(&buf[1], p, cnt); - set_page(priv, reg); + ret = set_page(priv, reg); + if (ret < 0) + return; ret = i2c_master_send(client, buf, cnt + 1); if (ret < 0) dev_err(&client->dev, "Error %d writing to 0x%x\n", ret, reg); } -static uint8_t +static int reg_read(struct tda998x_priv *priv, uint16_t reg) { uint8_t val = 0; - reg_read_range(priv, reg, &val, sizeof(val)); + int ret; + + ret = reg_read_range(priv, reg, &val, sizeof(val)); + if (ret < 0) + return ret; return val; } @@ -434,7 +445,9 @@ reg_write(struct tda998x_priv *priv, uint16_t reg, uint8_t val) uint8_t buf[] = {REG2ADDR(reg), val}; int ret; - set_page(priv, reg); + ret = set_page(priv, reg); + if (ret < 0) + return; ret = i2c_master_send(client, buf, ARRAY_SIZE(buf)); if (ret < 0) @@ -448,7 +461,9 @@ reg_write16(struct tda998x_priv *priv, uint16_t reg, uint16_t val) uint8_t buf[] = {REG2ADDR(reg), val >> 8, val}; int ret; - set_page(priv, reg); + ret = set_page(priv, reg); + if (ret < 0) + return; ret = i2c_master_send(client, buf, ARRAY_SIZE(buf)); if (ret < 0) @@ -458,13 +473,21 @@ reg_write16(struct tda998x_priv *priv, uint16_t reg, uint16_t val) static void reg_set(struct tda998x_priv *priv, uint16_t reg, uint8_t val) { - reg_write(priv, reg, reg_read(priv, reg) | val); + int old_val; + + old_val = reg_read(priv, reg); + if (old_val >= 0) + reg_write(priv, reg, old_val | val); } static void reg_clear(struct tda998x_priv *priv, uint16_t reg, uint8_t val) { - reg_write(priv, reg, reg_read(priv, reg) & ~val); + int old_val; + + old_val = reg_read(priv, reg); + if (old_val >= 0) + reg_write(priv, reg, old_val & ~val); } static void @@ -970,8 +993,10 @@ read_edid_block(struct drm_encoder *encoder, uint8_t *buf, int blk) /* wait for block read to complete: */ for (i = 100; i > 0; i--) { - uint8_t val = reg_read(priv, REG_INT_FLAGS_2); - if (val & INT_FLAGS_2_EDID_BLK_RD) + ret = reg_read(priv, REG_INT_FLAGS_2); + if (ret < 0) + return ret; + if (ret & INT_FLAGS_2_EDID_BLK_RD) break; msleep(1); } @@ -1134,6 +1159,7 @@ tda998x_encoder_init(struct i2c_client *client, struct drm_encoder_slave *encoder_slave) { struct tda998x_priv *priv; + int ret; priv = kzalloc(sizeof(*priv), GFP_KERNEL); if (!priv) @@ -1158,8 +1184,11 @@ tda998x_encoder_init(struct i2c_client *client, tda998x_reset(priv); /* read version: */ - priv->rev = reg_read(priv, REG_VERSION_LSB) | - reg_read(priv, REG_VERSION_MSB) << 8; + ret = reg_read(priv, REG_VERSION_LSB) | + (reg_read(priv, REG_VERSION_MSB) << 8); + if (ret < 0) + goto fail; + priv->rev = ret; /* mask off feature bits: */ priv->rev &= ~0x30; /* not-hdcp and not-scalar bit */