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 75ABB2566 for ; Tue, 18 Apr 2023 12:37:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EFE07C433D2; Tue, 18 Apr 2023 12:37:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1681821427; bh=4Qw3BGlNM2fmwGtPxT0weAgNI7WTvONXczuAN3z5Jzk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QChUEAB6vEjmKtKyGVqMa5SRa7Nl5EZLel+qiz+d1ABtyjW5SQLivZHuC0yFdzsa2 TzyI6XYL84shKAjpNXwU2vUkzy5qsydg3aFTgB/6UdhwE+xn715v0p3jrUSmSRYo09 F/qDl7N2EpMNGCV7BHBDP1rcOmrNB5HT3BlmDCAg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ivan Bornyakov , Andrew Lunn , "David S. Miller" Subject: [PATCH 5.10 094/124] net: sfp: initialize sfp->i2c_block_size at sfp allocation Date: Tue, 18 Apr 2023 14:21:53 +0200 Message-Id: <20230418120313.262122201@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230418120309.539243408@linuxfoundation.org> References: <20230418120309.539243408@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Ivan Bornyakov commit 813c2dd78618f108fdcf9cd726ea90f081ee2881 upstream. sfp->i2c_block_size is initialized at SFP module insertion in sfp_sm_mod_probe(). Because of that, if SFP module was never inserted since boot, sfp_read() call will lead to zero-length I2C read attempt, and not all I2C controllers are happy with zero-length reads. One way to issue sfp_read() on empty SFP cage is to execute ethtool -m. If SFP module was never plugged since boot, there will be a zero-length I2C read attempt. # ethtool -m xge0 i2c i2c-3: adapter quirk: no zero length (addr 0x0050, size 0, read) Cannot get Module EEPROM data: Operation not supported If SFP module was plugged then removed at least once, sfp->i2c_block_size will be initialized and ethtool -m will fail with different exit code and without I2C error # ethtool -m xge0 Cannot get Module EEPROM data: Remote I/O error Fix this by initializing sfp->i2_block_size at struct sfp allocation stage so no wild sfp_read() could issue zero-length I2C read. Signed-off-by: Ivan Bornyakov Fixes: 0d035bed2a4a ("net: sfp: VSOL V2801F / CarlitoxxPro CPGOS03-0490 v2.0 workaround") Cc: stable@vger.kernel.org Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/phy/sfp.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) --- a/drivers/net/phy/sfp.c +++ b/drivers/net/phy/sfp.c @@ -207,6 +207,12 @@ static const enum gpiod_flags gpio_flags */ #define SFP_PHY_ADDR 22 +/* SFP_EEPROM_BLOCK_SIZE is the size of data chunk to read the EEPROM + * at a time. Some SFP modules and also some Linux I2C drivers do not like + * reads longer than 16 bytes. + */ +#define SFP_EEPROM_BLOCK_SIZE 16 + struct sff_data { unsigned int gpios; bool (*module_supported)(const struct sfp_eeprom_id *id); @@ -1754,11 +1760,7 @@ static int sfp_sm_mod_probe(struct sfp * u8 check; int ret; - /* Some SFP modules and also some Linux I2C drivers do not like reads - * longer than 16 bytes, so read the EEPROM in chunks of 16 bytes at - * a time. - */ - sfp->i2c_block_size = 16; + sfp->i2c_block_size = SFP_EEPROM_BLOCK_SIZE; ret = sfp_read(sfp, false, 0, &id.base, sizeof(id.base)); if (ret < 0) { @@ -2385,6 +2387,7 @@ static struct sfp *sfp_alloc(struct devi return ERR_PTR(-ENOMEM); sfp->dev = dev; + sfp->i2c_block_size = SFP_EEPROM_BLOCK_SIZE; mutex_init(&sfp->sm_mutex); mutex_init(&sfp->st_mutex);