From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1F04F26B2DA; Mon, 19 Jan 2026 19:45:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768851946; cv=none; b=u8FC/z0MNSU6bCfyZvLa797oZkNFBuqaz2zUbcs8jV4Yd4BScfTB/nb1teW0ePUwik1Srg42/PHkBd7CyWHVbtHAcv/xFA8XFFMgbSSetozOR8SdiFmC1EB1bhOMgvcJELakSDLncnTsc4P0e6wvA1EI2V8IzKpacIT1A2PHjr8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1768851946; c=relaxed/simple; bh=X341cbVx+itPu3t/oJstdoSWqS2saf1YeOR3B3Pa+R8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RnudB/2YYiNIiJYW5UA8YmJmYulCNKuLQXYSimG4AKMZgbhnqc+QQiZH2NzT70JKiMZGqCqHl3o76y2FDcKV1aLHgXvTGaeif/4c2urIB6FPVSMrZJXjH79YtUZXcJons8ia3tqMo/kQ4KnIYKVuctPCmbXIGl6P6zvCvFwzbFs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=d99QQLeX; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="d99QQLeX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 25275C116C6; Mon, 19 Jan 2026 19:45:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1768851945; bh=X341cbVx+itPu3t/oJstdoSWqS2saf1YeOR3B3Pa+R8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=d99QQLeXX4eO61EWPaqwfQUyJbOnXBszqV6oLWUWqGONMh4bsOwk7VK4hE9doWyEZ RGfS4wBPGIZzpTVkZk9mvR9G+KL1TyZ5xZ9qGXJRvt2SyMYnNar5FqyGgqBbamVyX6 ZJQ69vR9TiMU3EmZkjmXoUYdqeJHkVStw+6apnw/RPPO735JFUfQXd3L0qMg5g7Ikm Zeo2qi3OILDMZfM34tlHot5yIYPulN4KeA9Tou1+y04YHOTyawRLDuWhOjfmTIALx2 GBe70GWxMWs0muQERzI868AER2eON1CxbYClcDMwcpqH6DkeSYmi8kyeYXxB3/X3/k aZEypPSc05ZzQ== From: Jakub Kicinski To: jelonek.jonas@gmail.com Cc: Jakub Kicinski , maxime.chevallier@bootlin.com, bjorn@mork.no, davem@davemloft.net, linux@armlinux.org.uk, pabeni@redhat.com, linux-kernel@vger.kernel.org, andrew@lunn.ch, netdev@vger.kernel.org, hkallweit1@gmail.com, edumazet@google.com Subject: Re: [net-next,v5] net: sfp: extend SMBus support Date: Mon, 19 Jan 2026 11:41:17 -0800 Message-ID: <20260119194117.1258120-1-kuba@kernel.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20260116113105.244592-1-jelonek.jonas@gmail.com> References: <20260116113105.244592-1-jelonek.jonas@gmail.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit This is an AI-generated review of your patch. The human sending this email has considered the AI review valid, or at least plausible. For local reproduction steps see https://netdev-ai.bots.linux.dev/ai-local.html --- net: sfp: extend SMBus support This patch extends SMBus support in the SFP driver from single-byte accesses to also support SMBus I2C block and word access, enabling more SMBus controllers to work with SFP modules. > diff --git a/drivers/net/phy/sfp.c b/drivers/net/phy/sfp.c > index 84bef5099dda..8f0b34a93ae8 100644 > --- a/drivers/net/phy/sfp.c > +++ b/drivers/net/phy/sfp.c [ ... ] > @@ -759,31 +773,55 @@ static int sfp_smbus_byte_write(struct sfp *sfp, bool a2, u8 dev_addr, > +static int sfp_smbus_write(struct sfp *sfp, bool a2, u8 dev_addr, void *buf, > + size_t len) > { > union i2c_smbus_data smbus_data; > u8 bus_addr = a2 ? 0x51 : 0x50; > + size_t this_len, transferred; > + u32 functionality; > u8 *data = buf; > int ret; > > + functionality = i2c_get_functionality(sfp->i2c); > + > while (len) { > - smbus_data.byte = *data; > - ret = i2c_smbus_xfer(sfp->i2c, bus_addr, 0, > - I2C_SMBUS_WRITE, dev_addr, > - I2C_SMBUS_BYTE_DATA, &smbus_data); > - if (ret) > + this_len = min(len, sfp->i2c_max_block_size); > + > + if (this_len > 2 && > + functionality & I2C_FUNC_SMBUS_WRITE_I2C_BLOCK) { > + smbus_data.block[0] = this_len; > + memcpy(&smbus_data.block[1], data, this_len); > + > + ret = i2c_smbus_xfer(sfp->i2c, bus_addr, 0, > + I2C_SMBUS_WRITE, dev_addr, > + I2C_SMBUS_WORD_DATA, &smbus_data); ^^^^^^^^^^^^^^^^^ Should this be I2C_SMBUS_I2C_BLOCK_DATA instead of I2C_SMBUS_WORD_DATA? The code checks for I2C_FUNC_SMBUS_WRITE_I2C_BLOCK support and sets up smbus_data.block[] with the length byte and data for a block transfer, but then calls i2c_smbus_xfer() with I2C_SMBUS_WORD_DATA protocol. For comparison, the read function correctly uses I2C_SMBUS_I2C_BLOCK_DATA when I2C_FUNC_SMBUS_READ_I2C_BLOCK is supported: if (this_len > 2 && functionality & I2C_FUNC_SMBUS_READ_I2C_BLOCK) { smbus_data.block[0] = this_len; ret = i2c_smbus_xfer(sfp->i2c, bus_addr, 0, I2C_SMBUS_READ, dev_addr, I2C_SMBUS_I2C_BLOCK_DATA, &smbus_data); With I2C_SMBUS_WORD_DATA, only 2 bytes from smbus_data.word would be written instead of the this_len bytes set up in smbus_data.block[]. The pointer then advances by transferred (this_len) bytes, effectively skipping data that was never written to the device. > + transferred = this_len; [ ... ] -- pw-bot: cr