From patchwork Tue Jan 12 16:41:28 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wolfram Sang X-Patchwork-Id: 361486 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8F073C4332D for ; Tue, 12 Jan 2021 16:42:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5B3C823109 for ; Tue, 12 Jan 2021 16:42:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727021AbhALQm1 (ORCPT ); Tue, 12 Jan 2021 11:42:27 -0500 Received: from www.zeus03.de ([194.117.254.33]:37370 "EHLO mail.zeus03.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388261AbhALQmS (ORCPT ); Tue, 12 Jan 2021 11:42:18 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=simple; d=sang-engineering.com; h= from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; s=k1; bh=COjMPOqL7pc0uU qyCZQPJcPRT2njX4Q7Fmh8pYBGCis=; b=rHNbVfps7GYEDFKCUfmJpwPhcP2KYa CyWNs7zo5IUlJPU6VZxnekx8BKAxCsb9/nBJIgugnnI3oF8XXk4fNXvqESLHZYyT kyMP6+wa4UUGgRHbE/rEkBG5saS/D4+vrSj7Kt5XMHvw7quOmiQrWiaFtG6b5/Jz Zg4gV8QmguKK8= Received: (qmail 2812461 invoked from network); 12 Jan 2021 17:41:36 +0100 Received: by mail.zeus03.de with ESMTPSA (TLS_AES_256_GCM_SHA384 encrypted, authenticated); 12 Jan 2021 17:41:36 +0100 X-UD-Smtp-Session: l3s3148p1@gPcmsra4StEgAwDPXwxzAHrEwO71dOp2 From: Wolfram Sang To: linux-i2c@vger.kernel.org Cc: Wolfram Sang , Hans Verkuil , Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH RFC 2/3] media: i2c: adv7842: remove open coded version of SMBus block read Date: Tue, 12 Jan 2021 17:41:28 +0100 Message-Id: <20210112164130.47895-3-wsa+renesas@sang-engineering.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210112164130.47895-1-wsa+renesas@sang-engineering.com> References: <20210112164130.47895-1-wsa+renesas@sang-engineering.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org The open coded version differs from the one in the core in one way: the buffer will be always copied back, even when the transfer failed. It looks like it is expected that the sanity check for a correct CRC and header will bail out later. Use the block read from the I2C core and propagate a potential errno further to the sanity check. Signed-off-by: Wolfram Sang --- Note: we could now make the error checking even stronger by checking if the number of received bytes is I2C_SMBUS_BLOCK_MAX. But to avoid regressions, I kept the logic as is, i.e. only check for errno. drivers/media/i2c/adv7511-v4l2.c | 40 +++++++++++--------------------- 1 file changed, 14 insertions(+), 26 deletions(-) diff --git a/drivers/media/i2c/adv7511-v4l2.c b/drivers/media/i2c/adv7511-v4l2.c index a3161d709015..0150f76dc6a6 100644 --- a/drivers/media/i2c/adv7511-v4l2.c +++ b/drivers/media/i2c/adv7511-v4l2.c @@ -214,36 +214,24 @@ static inline void adv7511_wr_and_or(struct v4l2_subdev *sd, u8 reg, u8 clr_mask adv7511_wr(sd, reg, (adv7511_rd(sd, reg) & clr_mask) | val_mask); } -static int adv_smbus_read_i2c_block_data(struct i2c_client *client, - u8 command, unsigned length, u8 *values) -{ - union i2c_smbus_data data; - int ret; - - if (length > I2C_SMBUS_BLOCK_MAX) - length = I2C_SMBUS_BLOCK_MAX; - data.block[0] = length; - - ret = i2c_smbus_xfer(client->adapter, client->addr, client->flags, - I2C_SMBUS_READ, command, - I2C_SMBUS_I2C_BLOCK_DATA, &data); - memcpy(values, data.block + 1, length); - return ret; -} - -static void adv7511_edid_rd(struct v4l2_subdev *sd, uint16_t len, uint8_t *buf) +static int adv7511_edid_rd(struct v4l2_subdev *sd, uint16_t len, uint8_t *buf) { struct adv7511_state *state = get_adv7511_state(sd); + s32 len; int i; - int err = 0; v4l2_dbg(1, debug, sd, "%s:\n", __func__); - for (i = 0; !err && i < len; i += I2C_SMBUS_BLOCK_MAX) - err = adv_smbus_read_i2c_block_data(state->i2c_edid, i, + for (i = 0; i < len; i += I2C_SMBUS_BLOCK_MAX) { + len = i2c_smbus_read_i2c_block_data(state->i2c_edid, i, I2C_SMBUS_BLOCK_MAX, buf + i); - if (err) - v4l2_err(sd, "%s: i2c read error\n", __func__); + if (len < 0) { + v4l2_err(sd, "%s: i2c read error\n", __func__); + return len; + } + } + + return 0; } static inline int adv7511_cec_read(struct v4l2_subdev *sd, u8 reg) @@ -1668,20 +1656,20 @@ static bool adv7511_check_edid_status(struct v4l2_subdev *sd) if (edidRdy & MASK_ADV7511_EDID_RDY) { int segment = adv7511_rd(sd, 0xc4); struct adv7511_edid_detect ed; + int err; if (segment >= EDID_MAX_SEGM) { v4l2_err(sd, "edid segment number too big\n"); return false; } v4l2_dbg(1, debug, sd, "%s: got segment %d\n", __func__, segment); - adv7511_edid_rd(sd, 256, &state->edid.data[segment * 256]); + err = adv7511_edid_rd(sd, 256, &state->edid.data[segment * 256]); adv7511_dbg_dump_edid(2, debug, sd, segment, &state->edid.data[segment * 256]); if (segment == 0) { state->edid.blocks = state->edid.data[0x7e] + 1; v4l2_dbg(1, debug, sd, "%s: %d blocks in total\n", __func__, state->edid.blocks); } - if (!edid_verify_crc(sd, segment) || - !edid_verify_header(sd, segment)) { + if (err < 0 || !edid_verify_crc(sd, segment) || !edid_verify_header(sd, segment)) { /* edid crc error, force reread of edid segment */ v4l2_err(sd, "%s: edid crc or header error\n", __func__); state->have_monitor = false;