From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id ECDB7C7EE23 for ; Wed, 24 May 2023 15:42:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237276AbjEXPmw (ORCPT ); Wed, 24 May 2023 11:42:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39650 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237303AbjEXPma (ORCPT ); Wed, 24 May 2023 11:42:30 -0400 Received: from mta-64-227.siemens.flowmailer.net (mta-64-227.siemens.flowmailer.net [185.136.64.227]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1A8C61716 for ; Wed, 24 May 2023 08:41:51 -0700 (PDT) Received: by mta-64-227.siemens.flowmailer.net with ESMTPSA id 202305241540502efe19dc95d03e040e for ; Wed, 24 May 2023 17:40:50 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=fm1; d=siemens.com; i=alexander.sverdlin@siemens.com; h=Date:From:Subject:To:Message-ID:MIME-Version:Content-Type:Content-Transfer-Encoding:Cc; bh=ZleL3ST0XPNGt2fgQSXW/cK2rv3FOpZbAigNjtSUHpo=; b=Whtsf3wsUzZRPWC2b2MKrRj//aDpTZWpoxk2yrNtcz6L2rzh/g89piOB6KxKvavL21nSHz H2M2xfC1o48MyIri4KaltHmlHri2QW9AceMgY1TEkDff5jc/PpLq3EI9egyJtLl06LSE7sf2 lGKVRAr4qK8c0oNPgaeke9XMNG3XQ=; From: "A. Sverdlin" To: linux-integrity@vger.kernel.org Cc: Alexander Sverdlin , Peter Huewe , Jarkko Sakkinen , Jason Gunthorpe , linux-kernel@vger.kernel.org, Alexander Steffen , Michael Haener Subject: [PATCH 1/2] tpm: tis_i2c: Limit read bursts to I2C_SMBUS_BLOCK_MAX (32) bytes Date: Wed, 24 May 2023 17:40:39 +0200 Message-Id: <20230524154040.1204030-1-alexander.sverdlin@siemens.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Flowmailer-Platform: Siemens Feedback-ID: 519:519-456497:519-21489:flowmailer Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org From: Alexander Sverdlin 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 Fixes: bbc23a07b072 ("tpm: Add tpm_tis_i2c backend for tpm_tis_core") Tested-by: Michael Haener Signed-off-by: Alexander Sverdlin --- 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) -- 2.40.1