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 2BABC20F8F for ; Fri, 21 Jul 2023 19:20:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A10CBC433C7; Fri, 21 Jul 2023 19:20:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689967230; bh=zQ9vyPPsAm83hfZGIgmAi3Wx4iQ3/nUJvyP6XGYBxd0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=H5hQSmmuuTFZTK/978a9dlosP536D9ypGl2rehzAk8gQmQRoTyISe51gQsUhqKSo/ Yk2cwYgliy2rJGdNPuseXHNJs9IIKnzNAg1vdt37mY9c6ARK3C9sRKphR0iD/aBtNQ ztoawZsekyg+a2DOXAgm7R6QnBVVXMlHYWDUu/LM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Michael Haener , Alexander Sverdlin , Jarkko Sakkinen , Jerry Snitselaar Subject: [PATCH 6.1 090/223] tpm: tis_i2c: Limit read bursts to I2C_SMBUS_BLOCK_MAX (32) bytes Date: Fri, 21 Jul 2023 18:05:43 +0200 Message-ID: <20230721160524.698730965@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230721160520.865493356@linuxfoundation.org> References: <20230721160520.865493356@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: Alexander Sverdlin commit f3b70b6e3390bfdf18fdd7d278a72a12784fdcce upstream. Underlying I2C bus drivers not always support longer transfers and imx-lpi2c for instance doesn't. SLB 9673 offers 427-bytes packets. Visible symptoms are: tpm tpm0: Error left over data tpm tpm0: tpm_transmit: tpm_recv: error -5 tpm_tis_i2c: probe of 1-002e failed with error -5 Cc: stable@vger.kernel.org # v5.20+ Fixes: bbc23a07b072 ("tpm: Add tpm_tis_i2c backend for tpm_tis_core") Tested-by: Michael Haener Signed-off-by: Alexander Sverdlin Reviewed-by: Jarkko Sakkinen Reviewed-by: Jerry Snitselaar Signed-off-by: Jarkko Sakkinen Signed-off-by: Greg Kroah-Hartman --- drivers/char/tpm/tpm_tis_i2c.c | 37 ++++++++++++++++++++-------------- 1 file changed, 22 insertions(+), 15 deletions(-) diff --git a/drivers/char/tpm/tpm_tis_i2c.c b/drivers/char/tpm/tpm_tis_i2c.c index c8c34adc14c0..106fd20d94e4 100644 --- a/drivers/char/tpm/tpm_tis_i2c.c +++ b/drivers/char/tpm/tpm_tis_i2c.c @@ -189,21 +189,28 @@ static int tpm_tis_i2c_read_bytes(struct tpm_tis_data *data, u32 addr, u16 len, int ret; for (i = 0; i < TPM_RETRY; i++) { - /* write register */ - msg.len = sizeof(reg); - msg.buf = ® - msg.flags = 0; - ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg); - if (ret < 0) - return ret; - - /* read data */ - msg.buf = result; - msg.len = len; - msg.flags = I2C_M_RD; - ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg); - if (ret < 0) - return ret; + u16 read = 0; + + while (read < len) { + /* write register */ + msg.len = sizeof(reg); + msg.buf = ® + msg.flags = 0; + ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg); + if (ret < 0) + return ret; + + /* read data */ + msg.buf = result + read; + msg.len = len - read; + msg.flags = I2C_M_RD; + if (msg.len > I2C_SMBUS_BLOCK_MAX) + msg.len = I2C_SMBUS_BLOCK_MAX; + ret = tpm_tis_i2c_retry_transfer_until_ack(data, &msg); + if (ret < 0) + return ret; + read += msg.len; + } ret = tpm_tis_i2c_sanity_check_read(reg, len, result); if (ret == 0) -- 2.41.0