From patchwork Wed Jul 8 18:17:39 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ellen Wang X-Patchwork-Id: 6750511 X-Patchwork-Delegate: jikos@jikos.cz Return-Path: X-Original-To: patchwork-linux-input@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 5B4CDC05AC for ; Wed, 8 Jul 2015 18:17:49 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7403F20629 for ; Wed, 8 Jul 2015 18:17:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2C09020628 for ; Wed, 8 Jul 2015 18:17:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758935AbbGHSRq (ORCPT ); Wed, 8 Jul 2015 14:17:46 -0400 Received: from mail-pa0-f45.google.com ([209.85.220.45]:35279 "EHLO mail-pa0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755863AbbGHSRp (ORCPT ); Wed, 8 Jul 2015 14:17:45 -0400 Received: by pactm7 with SMTP id tm7so135741904pac.2 for ; Wed, 08 Jul 2015 11:17:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cumulusnetworks.com; s=google; h=from:to:cc:subject:date:message-id; bh=/kayxSn8LycGMjoCJKz/ne8E571FRn4kk5MlXEc7Wq8=; b=Juq/jCgiI/RJJxFgeJSF8Hm6xGJFoA90NMDviDV8XLvM9989kZbHSef3HDAFlhUJc8 6AOLFGKwiLvQt0znzHlG4JnAhlHS7u8jmSplB9x2FBSFZSg/7fSyMAbcmYVqHiCDiEJG Xujaszi2gJ7pFXxJj11jblBRmvh8e8FgJZx9A= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=/kayxSn8LycGMjoCJKz/ne8E571FRn4kk5MlXEc7Wq8=; b=WrOF8s2UHRUUsPwXVPd1D9MQVq+f8rk+zavQtou8TcoOA69Da0Hu8BLW8eLNPDNkE9 GkRsKMV+iQBkmIfWtwPL9xmu/2hAmH3hsMv5AdsEv2bIAr/uARG5fKO+Au+lthpsYsVR divrylWZecGoQXC0X7USaVKs6tOUFfJAFKz3XP9lCXEgTjn0Vm/4wAoD5SmiPLUHzP2b M8g7pBOhssAegPtQAOtOdETJAwbnzUDi8/Cv8khbs+wOt8xbRmcBIxku4kMOWXNjA+Ry dMsfw27ZDnmMxBD818OuOK8VfBxTNvisZOZ+Ln3ZLsxiWdh+B0NcWIeJIGjclayWPFpC rHEw== X-Gm-Message-State: ALoCoQmbJ+n0T4PZSUB1hwkv6M7EcSkFbLaKtlqHyXzEAjo3EDMUUke4m8V1s3tlwFh4/IzSD0b+ X-Received: by 10.70.101.106 with SMTP id ff10mr23398480pdb.162.1436379464686; Wed, 08 Jul 2015 11:17:44 -0700 (PDT) Received: from monster-01.cumulusnetworks.com ([216.129.126.126]) by smtp.gmail.com with ESMTPSA id pz9sm3212509pbb.93.2015.07.08.11.17.43 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 08 Jul 2015 11:17:43 -0700 (PDT) From: Ellen Wang To: borneo.antonio@gmail.com, dbarksdale@uplogix.com, jkosina@suse.cz, linux-input@vger.kernel.org, linux-i2c@vger.kernel.org Cc: ellen@cumulusnetworks.com Subject: [PATCH v3] HID: cp2112: support large i2c transfers in hid-cp2112 Date: Wed, 8 Jul 2015 11:17:39 -0700 Message-Id: <1436379459-8263-1-git-send-email-ellen@cumulusnetworks.com> X-Mailer: git-send-email 1.9.1 Sender: linux-input-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org X-Spam-Status: No, score=-7.5 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD,T_DKIM_INVALID,UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP cp2112_i2c_xfer() only reads up to 61 bytes, returning EIO on longers reads. The fix is to wrap a loop around cp2112_read() to pick up all the returned data. Signed-off-by: Ellen Wang Tested-by: Antonio Borneo Reviewed-by: Antonio Borneo --- This is the updated patch with a check for 0 return from cp2112_read(). I tested it with a suitable delay in the loop to trigger the cp2112_raw_event() overrun bug, which must be fixed before this patch is applied. --- drivers/hid/hid-cp2112.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) diff --git a/drivers/hid/hid-cp2112.c b/drivers/hid/hid-cp2112.c index 3318de6..80e3488 100644 --- a/drivers/hid/hid-cp2112.c +++ b/drivers/hid/hid-cp2112.c @@ -509,13 +509,30 @@ static int cp2112_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, if (!(msgs->flags & I2C_M_RD)) goto finish; - ret = cp2112_read(dev, msgs->buf, msgs->len); - if (ret < 0) - goto power_normal; - if (ret != msgs->len) { - hid_warn(hdev, "short read: %d < %d\n", ret, msgs->len); - ret = -EIO; - goto power_normal; + for (count = 0; count < msgs->len;) { + ret = cp2112_read(dev, msgs->buf + count, msgs->len - count); + if (ret < 0) + goto power_normal; + if (ret == 0) { + hid_err(hdev, "read returned 0\n"); + ret = -EIO; + goto power_normal; + } + count += ret; + if (count > msgs->len) { + /* + * The hardware returned too much data. + * This is mostly harmless because cp2112_read() + * has a limit check so didn't overrun our + * buffer. Nevertheless, we return an error + * because something is seriously wrong and + * it shouldn't go unnoticed. + */ + hid_err(hdev, "long read: %d > %zd\n", + ret, msgs->len - count + ret); + ret = -EIO; + goto power_normal; + } } finish: