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 X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 04AE3C433C1 for ; Fri, 19 Mar 2021 16:34:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA07A6192F for ; Fri, 19 Mar 2021 16:34:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229996AbhCSQdl (ORCPT ); Fri, 19 Mar 2021 12:33:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53806 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230015AbhCSQdR (ORCPT ); Fri, 19 Mar 2021 12:33:17 -0400 Received: from mail-ed1-x52c.google.com (mail-ed1-x52c.google.com [IPv6:2a00:1450:4864:20::52c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 000D3C06174A for ; Fri, 19 Mar 2021 09:33:16 -0700 (PDT) Received: by mail-ed1-x52c.google.com with SMTP id j3so11475313edp.11 for ; Fri, 19 Mar 2021 09:33:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=YE7uFy2N7j2Ja5TOSYdTQkiwcsHL4N5yY1QGWWdXy10=; b=He38tQ+fy+Wx6K56wVxIevmoLGX/xBZoYyKZa3qarQu2hGw9a+mQ2JtflCP4/K2dHm 7gRA1mOuuCqmKSJfyWSRTfXO2XGmTpvSesE0hAea6l0XTdO1gT1AfKAwByIoU4GV7nUg r0H6hScisRGfe+wLE98b1Yr7XLCOvLUTY1Mga1C3sHZKNnmDl6Hqw9fFyxiIEky2CtDg vn6qh5MMlu0nbvDRDqgw+RwO370oDAhR+rH2JF2h58TxAQpVLw9/b3OkhRkEMn2k/9N7 EdEtye9rT1KB12J1ePdYeSJkbrpRGxRgefLPJvO0ocOF6uwDRj97sWymvCxuLFV98aK6 8Zdg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=YE7uFy2N7j2Ja5TOSYdTQkiwcsHL4N5yY1QGWWdXy10=; b=Yl/bk9FHHYezgac/x3w3xDLrT7BKV/FMAF0UDNslizR7MQTesWgGlLANxJZ2RK+6HG nqRGRhMJ3IwzIrSbL+vmVd43opgKlY+UqSJsMzrBx3c32YZKIJ2IvTbQm0jCmO/xGQz2 +7XcQgdfkWgHWwvQ/tI1axEjZy+J8C6Jp76smXvuWHi+nxHCzmFKZG0/Ve8IOkGzXo8i IhQghF8dQJvr4uFZ5LR+fZFXDRzuY1Z0ODVj8UFBSlF3e24wIDyxl8hhsqmrd3Iv+kdl xOSMd+SXmjIIuE3zl7iwyR9+iGkaYwWzDV0mAhqpCX8LMePcZfc4Qub6bsQMbNiQilY/ snaA== X-Gm-Message-State: AOAM532t5floxHJsbWpGa86V45Q8xZhDOh7pc7fRGglLeSlIdIREPO99 XnQxjVq9KgN39cw6i1e5mrM= X-Google-Smtp-Source: ABdhPJzWSXhZyoGiCE8yRQcYAIrGDHZ1p4QMBMo2rB4CU3kpG29c82lAJP7541RbezjCx1JIgpKJ8Q== X-Received: by 2002:aa7:cd64:: with SMTP id ca4mr10421890edb.334.1616171595500; Fri, 19 Mar 2021 09:33:15 -0700 (PDT) Received: from michael-VirtualBox (cbl217-132-244-50.bb.netvision.net.il. [217.132.244.50]) by smtp.gmail.com with ESMTPSA id kj3sm3960809ejc.117.2021.03.19.09.33.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Mar 2021 09:33:15 -0700 (PDT) Date: Fri, 19 Mar 2021 18:33:12 +0200 From: Michael Zaidman To: Dan Carpenter Cc: linux-input@vger.kernel.org Subject: Re: [bug report] HID: ft260: add usb hid to i2c host bridge driver Message-ID: <20210319163312.GA1940@michael-VirtualBox> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-input@vger.kernel.org On Thu, Mar 18, 2021 at 01:39:53PM +0300, Dan Carpenter wrote: > > drivers/hid/hid-ft260.c > 1017 static int ft260_raw_event(struct hid_device *hdev, struct hid_report *report, > 1018 u8 *data, int size) > 1019 { > 1020 struct ft260_device *dev = hid_get_drvdata(hdev); > 1021 struct ft260_i2c_input_report *xfer = (void *)data; > 1022 > 1023 if (xfer->report >= FT260_I2C_REPORT_MIN && > 1024 xfer->report <= FT260_I2C_REPORT_MAX) { > 1025 ft260_dbg("i2c resp: rep %#02x len %d\n", xfer->report, > 1026 xfer->length); > 1027 > 1028 memcpy(&dev->read_buf[dev->read_idx], &xfer->data, > 1029 xfer->length); > > Do we need to check if "xfer->len <= dev->read_len"? The dev->read_len is a total length to be read, passed into ft260_i2c_read() by a user. This length is divided into 60 bytes chanks to be retrieved from the ft260 controller. The ft260_raw_event() receives these chanks and counts the total number of bytes received in read_idx. Once it matches the read_len, we conclude on the i2c read transfer completion. We do not need to check the xfer->len against the dev->read_len since the ft260 controller never returns more bytes than was asked to read. > > 1030 dev->read_idx += xfer->length; > 1031 > 1032 if (dev->read_idx == dev->read_len) > 1033 complete(&dev->wait); > 1034 > 1035 } else { > 1036 hid_err(hdev, "unknown report: %#02x\n", xfer->report); > 1037 return 0; > 1038 } > 1039 return 1; > 1040 } > > regards, > dan carpenter