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[85.228.174.190]) by smtp.gmail.com with ESMTPSA id m28sm1491799lfo.10.2020.12.04.01.37.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 04 Dec 2020 01:37:13 -0800 (PST) Received: from johan by xi.terra with local (Exim 4.93.0.4) (envelope-from ) id 1kl7X8-0005Ni-UI; Fri, 04 Dec 2020 10:37:47 +0100 Date: Fri, 4 Dec 2020 10:37:46 +0100 From: Johan Hovold To: Himadri Pandya Message-ID: References: <20201104064703.15123-1-himadrispandya@gmail.com> <20201104064703.15123-6-himadrispandya@gmail.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201104064703.15123-6-himadrispandya@gmail.com> Cc: linux-usb@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, johan@kernel.org, linux-kernel@vger.kernel.org Subject: Re: [Linux-kernel-mentees] [PATCH 05/15] usb: serial: cypress_m8: use usb_control_msg_recv() and usb_control_msg_send() X-BeenThere: linux-kernel-mentees@lists.linuxfoundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-kernel-mentees-bounces@lists.linuxfoundation.org Sender: "Linux-kernel-mentees" On Wed, Nov 04, 2020 at 12:16:53PM +0530, Himadri Pandya wrote: > The new usb_control_msg_recv() and usb_control_msg_send() nicely wraps > usb_control_msg() with proper error check. Hence use the wrappers > instead of calling usb_control_msg() directly. > > Signed-off-by: Himadri Pandya > --- > drivers/usb/serial/cypress_m8.c | 38 +++++++++++++++++---------------- > 1 file changed, 20 insertions(+), 18 deletions(-) > > diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c > index cc028601c388..4d66cab8eece 100644 > --- a/drivers/usb/serial/cypress_m8.c > +++ b/drivers/usb/serial/cypress_m8.c > @@ -341,20 +341,21 @@ static int cypress_serial_control(struct tty_struct *tty, > feature_buffer[4]); > > do { > - retval = usb_control_msg(port->serial->dev, > - usb_sndctrlpipe(port->serial->dev, 0), > - HID_REQ_SET_REPORT, > - USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS, > - 0x0300, 0, feature_buffer, > - feature_len, 500); > + retval = usb_control_msg_send(port->serial->dev, 0, > + HID_REQ_SET_REPORT, > + USB_DIR_OUT | > + USB_RECIP_INTERFACE | > + USB_TYPE_CLASS, 0x0300, > + 0, feature_buffer, > + feature_len, 500, > + GFP_KERNEL); > > if (tries++ >= 3) > break; > > - } while (retval != feature_len && > - retval != -ENODEV); > + } while (retval != -ENODEV); Here you actually break the logic; after this change the driver will always retry as the test for success is removed. > > - if (retval != feature_len) { > + if (retval) { > dev_err(dev, "%s - failed sending serial line settings - %d\n", > __func__, retval); > cypress_set_dead(port); > @@ -379,19 +380,20 @@ static int cypress_serial_control(struct tty_struct *tty, > } > dev_dbg(dev, "%s - retrieving serial line settings\n", __func__); > do { > - retval = usb_control_msg(port->serial->dev, > - usb_rcvctrlpipe(port->serial->dev, 0), > - HID_REQ_GET_REPORT, > - USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS, > - 0x0300, 0, feature_buffer, > - feature_len, 500); > + retval = usb_control_msg_recv(port->serial->dev, 0, > + HID_REQ_GET_REPORT, > + USB_DIR_IN | > + USB_RECIP_INTERFACE | > + USB_TYPE_CLASS, 0x0300, > + 0, feature_buffer, > + feature_len, 500, > + GFP_KERNEL); > > if (tries++ >= 3) > break; > - } while (retval != feature_len > - && retval != -ENODEV); > + } while (retval != -ENODEV); Same here. > > - if (retval != feature_len) { > + if (retval) { > dev_err(dev, "%s - failed to retrieve serial line settings - %d\n", > __func__, retval); > cypress_set_dead(port); As the driver is already using a DMA-able buffer and is reusing it for every retry as well, this change is now introducing redundant memdup + memcpy for each call. I suggest just dropping this one. Johan _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees 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=-14.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 B1C33C19425 for ; Fri, 4 Dec 2020 09:38:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6AB57227C3 for ; Fri, 4 Dec 2020 09:38:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729543AbgLDJiE (ORCPT ); Fri, 4 Dec 2020 04:38:04 -0500 Received: from mail-lf1-f65.google.com ([209.85.167.65]:45485 "EHLO mail-lf1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387584AbgLDJiD (ORCPT ); Fri, 4 Dec 2020 04:38:03 -0500 Received: by mail-lf1-f65.google.com with SMTP id z21so6759338lfe.12; Fri, 04 Dec 2020 01:37:40 -0800 (PST) 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=rCis0KUuTW9MGXUF26gw5+ReaZfnt50i53XCblKc1Wc=; b=U5jxWijhIx5rCV0EoGvv+g98pop9GOElmKxE3ExecRKyZuQTigy89Fhn/PL9mZ0baU 3LNYqcdE3JbvthoFAX0Rj5nc2s92CyZC8QrK/Gm38P2lS7tx+C08g6T3ZBCWHUPFHqT6 wJ1Gno1T9vbX1P0WmQhu+VwPEj/DQcUXPdie5E/YoeJAO+5JZfX7I8XgQwrcMvWZONKN nSSS0kIemxsrc6tRAnoBZzRwl0WeP1Gd06yPTvaNeug372hTQeqCJ0mfiARFOBN+1KS+ GWsQZDUEMcC/e+SZVc1XmRLVPIRrA/k8vBjlopW+/fChgERbx2V7Gze+xBhog+d0TGuV m+DA== X-Gm-Message-State: AOAM531DHcZ/JRSyFVdTNyciPPTXD9GnZVZNqKzPzmOvjJYQvS+LYytd Mn9z45etmI//SVM1Pt5+Jwk= X-Google-Smtp-Source: ABdhPJylHu3wEWK+g+aeq+PFtsJgpSrucwZEYGSqo2cpTcXTOSxrbVnYcNp1CRlFhYPcZT6/WnGu3Q== X-Received: by 2002:ac2:50d2:: with SMTP id h18mr2723674lfm.169.1607074633924; Fri, 04 Dec 2020 01:37:13 -0800 (PST) Received: from xi.terra (c-beaee455.07-184-6d6c6d4.bbcust.telenor.se. [85.228.174.190]) by smtp.gmail.com with ESMTPSA id m28sm1491799lfo.10.2020.12.04.01.37.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 04 Dec 2020 01:37:13 -0800 (PST) Received: from johan by xi.terra with local (Exim 4.93.0.4) (envelope-from ) id 1kl7X8-0005Ni-UI; Fri, 04 Dec 2020 10:37:47 +0100 Date: Fri, 4 Dec 2020 10:37:46 +0100 From: Johan Hovold To: Himadri Pandya Cc: johan@kernel.org, gregkh@linuxfoundation.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org Subject: Re: [PATCH 05/15] usb: serial: cypress_m8: use usb_control_msg_recv() and usb_control_msg_send() Message-ID: References: <20201104064703.15123-1-himadrispandya@gmail.com> <20201104064703.15123-6-himadrispandya@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201104064703.15123-6-himadrispandya@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Wed, Nov 04, 2020 at 12:16:53PM +0530, Himadri Pandya wrote: > The new usb_control_msg_recv() and usb_control_msg_send() nicely wraps > usb_control_msg() with proper error check. Hence use the wrappers > instead of calling usb_control_msg() directly. > > Signed-off-by: Himadri Pandya > --- > drivers/usb/serial/cypress_m8.c | 38 +++++++++++++++++---------------- > 1 file changed, 20 insertions(+), 18 deletions(-) > > diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c > index cc028601c388..4d66cab8eece 100644 > --- a/drivers/usb/serial/cypress_m8.c > +++ b/drivers/usb/serial/cypress_m8.c > @@ -341,20 +341,21 @@ static int cypress_serial_control(struct tty_struct *tty, > feature_buffer[4]); > > do { > - retval = usb_control_msg(port->serial->dev, > - usb_sndctrlpipe(port->serial->dev, 0), > - HID_REQ_SET_REPORT, > - USB_DIR_OUT | USB_RECIP_INTERFACE | USB_TYPE_CLASS, > - 0x0300, 0, feature_buffer, > - feature_len, 500); > + retval = usb_control_msg_send(port->serial->dev, 0, > + HID_REQ_SET_REPORT, > + USB_DIR_OUT | > + USB_RECIP_INTERFACE | > + USB_TYPE_CLASS, 0x0300, > + 0, feature_buffer, > + feature_len, 500, > + GFP_KERNEL); > > if (tries++ >= 3) > break; > > - } while (retval != feature_len && > - retval != -ENODEV); > + } while (retval != -ENODEV); Here you actually break the logic; after this change the driver will always retry as the test for success is removed. > > - if (retval != feature_len) { > + if (retval) { > dev_err(dev, "%s - failed sending serial line settings - %d\n", > __func__, retval); > cypress_set_dead(port); > @@ -379,19 +380,20 @@ static int cypress_serial_control(struct tty_struct *tty, > } > dev_dbg(dev, "%s - retrieving serial line settings\n", __func__); > do { > - retval = usb_control_msg(port->serial->dev, > - usb_rcvctrlpipe(port->serial->dev, 0), > - HID_REQ_GET_REPORT, > - USB_DIR_IN | USB_RECIP_INTERFACE | USB_TYPE_CLASS, > - 0x0300, 0, feature_buffer, > - feature_len, 500); > + retval = usb_control_msg_recv(port->serial->dev, 0, > + HID_REQ_GET_REPORT, > + USB_DIR_IN | > + USB_RECIP_INTERFACE | > + USB_TYPE_CLASS, 0x0300, > + 0, feature_buffer, > + feature_len, 500, > + GFP_KERNEL); > > if (tries++ >= 3) > break; > - } while (retval != feature_len > - && retval != -ENODEV); > + } while (retval != -ENODEV); Same here. > > - if (retval != feature_len) { > + if (retval) { > dev_err(dev, "%s - failed to retrieve serial line settings - %d\n", > __func__, retval); > cypress_set_dead(port); As the driver is already using a DMA-able buffer and is reusing it for every retry as well, this change is now introducing redundant memdup + memcpy for each call. I suggest just dropping this one. Johan