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 B0BFBC433FE for ; Wed, 27 Apr 2022 05:38:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1357895AbiD0FmC (ORCPT ); Wed, 27 Apr 2022 01:42:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47772 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232148AbiD0FmB (ORCPT ); Wed, 27 Apr 2022 01:42:01 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 080F514DE8F; Tue, 26 Apr 2022 22:38:51 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id BE456B824E6; Wed, 27 Apr 2022 05:38:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 39A00C385A9; Wed, 27 Apr 2022 05:38:47 +0000 (UTC) Message-ID: <8cab70e2-cd3f-da75-9e6a-1d63e33e6e24@xs4all.nl> Date: Wed, 27 Apr 2022 07:38:45 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH] media: stkwebcam: move stk_camera_read_reg() scratch buffer to struct stk_camera Content-Language: en-US To: trix@redhat.com, mchehab@kernel.org, cai.huoqing@linux.dev, paskripkin@gmail.com, xose.vazquez@gmail.com Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org References: <20220312173049.1410977-1-trix@redhat.com> From: Hans Verkuil In-Reply-To: <20220312173049.1410977-1-trix@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Tom, On 12/03/2022 18:30, trix@redhat.com wrote: > From: Tom Rix > > In stk_camera_read_reg() a single byte buffer is alloc-ed and > freed on every function call. Since the size is known, > move the buffer to the struct stk_camera where it will be alloc-ed > and freed once. I read the replies to this patch, but I am not certain if you still want this patch to be merged, or will make a v2. I have no problem applying this patch as-is, but I just want to have confirmation that there won't be a v2. Regards, Hans > > Signed-off-by: Tom Rix > --- > drivers/media/usb/stkwebcam/stk-webcam.c | 11 ++--------- > drivers/media/usb/stkwebcam/stk-webcam.h | 2 ++ > 2 files changed, 4 insertions(+), 9 deletions(-) > > diff --git a/drivers/media/usb/stkwebcam/stk-webcam.c b/drivers/media/usb/stkwebcam/stk-webcam.c > index 5b822214ccc5c..787edb3d47c23 100644 > --- a/drivers/media/usb/stkwebcam/stk-webcam.c > +++ b/drivers/media/usb/stkwebcam/stk-webcam.c > @@ -150,25 +150,18 @@ int stk_camera_write_reg(struct stk_camera *dev, u16 index, u8 value) > int stk_camera_read_reg(struct stk_camera *dev, u16 index, u8 *value) > { > struct usb_device *udev = dev->udev; > - unsigned char *buf; > int ret; > > - buf = kmalloc(sizeof(u8), GFP_KERNEL); > - if (!buf) > - return -ENOMEM; > - > ret = usb_control_msg(udev, usb_rcvctrlpipe(udev, 0), > 0x00, > USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE, > 0x00, > index, > - buf, > + &dev->read_reg_scratch, > sizeof(u8), > 500); > if (ret >= 0) > - *value = *buf; > - > - kfree(buf); > + *value = dev->read_reg_scratch; > > if (ret < 0) > return ret; > diff --git a/drivers/media/usb/stkwebcam/stk-webcam.h b/drivers/media/usb/stkwebcam/stk-webcam.h > index 14519e5308b18..136decffe9ced 100644 > --- a/drivers/media/usb/stkwebcam/stk-webcam.h > +++ b/drivers/media/usb/stkwebcam/stk-webcam.h > @@ -105,6 +105,8 @@ struct stk_camera { > struct list_head sio_avail; > struct list_head sio_full; > unsigned sequence; > + > + u8 read_reg_scratch; > }; > > #define vdev_to_camera(d) container_of(d, struct stk_camera, vdev)