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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 77754C48BD1 for ; Thu, 10 Jun 2021 17:29:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5542A601FD for ; Thu, 10 Jun 2021 17:29:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230402AbhFJRa4 (ORCPT ); Thu, 10 Jun 2021 13:30:56 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57786 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229802AbhFJRaz (ORCPT ); Thu, 10 Jun 2021 13:30:55 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A638FC061574; Thu, 10 Jun 2021 10:28:58 -0700 (PDT) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id DADC28D4; Thu, 10 Jun 2021 19:28:54 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1623346135; bh=sB/vPmsUpxNwX3o7X6dukEKBxTdhaGoLN9eEvahqVTs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qw2KxzdqcoipsyoNzLGyrhmA9Vr6EGsXuUVG2KueYrN7FxLm2NKrm5fGktJV1ifT5 DseUl+fluUP9G8uXvA+w22FpPoRX4kC/u1zxTR+rSSxUWjZt/c/K42eRQECv2rRGKe UfLJSplr1jokw/rZDegAZQBTeOe+LUF9dZVpmQmA= Date: Thu, 10 Jun 2021 20:28:36 +0300 From: Laurent Pinchart To: Ricardo Ribalda Cc: Mauro Carvalho Chehab , Hans Verkuil , Sergey Senozhatsky , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, tfiga@chromium.org Subject: Re: [PATCH v9 16/22] media: uvcvideo: Return -EACCES to inactive controls Message-ID: References: <20210326095840.364424-1-ribalda@chromium.org> <20210326095840.364424-17-ribalda@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210326095840.364424-17-ribalda@chromium.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Ricardo, Thank you for the patch. On Fri, Mar 26, 2021 at 10:58:34AM +0100, Ricardo Ribalda wrote: > If a control is inactive return -EACCES to let the userspace know that > the value will not be applied automatically when the control is active > again. Isn't the device supposed to stall the control set in that case, with the bRequestErrorCode set to "Wrong state", which uvc_query_ctrl() translates to -EACCES already ? Could you elaborate on why this patch is needed ? > Suggested-by: Hans Verkuil > Signed-off-by: Ricardo Ribalda > --- > drivers/media/usb/uvc/uvc_ctrl.c | 71 +++++++++++++++++++++----------- > 1 file changed, 48 insertions(+), 23 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c > index bcebf9d1a46f..d9d4add1e813 100644 > --- a/drivers/media/usb/uvc/uvc_ctrl.c > +++ b/drivers/media/usb/uvc/uvc_ctrl.c > @@ -1082,13 +1082,36 @@ static const char *uvc_map_get_name(const struct uvc_control_mapping *map) > return "Unknown Control"; > } > > +static bool uvc_ctrl_is_inactive(struct uvc_video_chain *chain, > + struct uvc_control *ctrl, > + struct uvc_control_mapping *mapping) > +{ > + struct uvc_control_mapping *master_map = NULL; > + struct uvc_control *master_ctrl = NULL; > + s32 val; > + int ret; > + > + if (!mapping->master_id) > + return false; > + > + __uvc_find_control(ctrl->entity, mapping->master_id, &master_map, > + &master_ctrl, 0); > + > + if (!master_ctrl || !(master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR)) > + return false; > + > + ret = __uvc_ctrl_get(chain, master_ctrl, master_map, &val); > + if (ret < 0 || val == mapping->master_manual) > + return false; > + > + return true; > +} > + > static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain, > struct uvc_control *ctrl, > struct uvc_control_mapping *mapping, > struct v4l2_queryctrl *v4l2_ctrl) > { > - struct uvc_control_mapping *master_map = NULL; > - struct uvc_control *master_ctrl = NULL; > const struct uvc_menu_info *menu; > unsigned int i; > > @@ -1104,18 +1127,8 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain, > if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR)) > v4l2_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY; > > - if (mapping->master_id) > - __uvc_find_control(ctrl->entity, mapping->master_id, > - &master_map, &master_ctrl, 0); > - if (master_ctrl && (master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR)) { > - s32 val; > - int ret = __uvc_ctrl_get(chain, master_ctrl, master_map, &val); > - if (ret < 0) > - return ret; There's a small change in behaviour here, the driver used to return an error, now it will ignore it. Is it intentional ? > - > - if (val != mapping->master_manual) > - v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE; > - } > + if (uvc_ctrl_is_inactive(chain, ctrl, mapping)) > + v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE; > > if (!ctrl->cached) { > int ret = uvc_ctrl_populate_cache(chain, ctrl); > @@ -1638,25 +1651,37 @@ static int uvc_ctrl_commit_entity(struct uvc_device *dev, > return 0; > } > > -static int uvc_ctrl_find_ctrlidx(struct uvc_entity *entity, > +static int uvc_ctrl_commit_error(struct uvc_video_chain *chain, > + struct uvc_entity *entity, > struct v4l2_ext_controls *ctrls, > - struct uvc_control *uvc_control) > + struct uvc_control *err_control, > + int ret) > { > struct uvc_control_mapping *mapping; > struct uvc_control *ctrl_found; > unsigned int i; > > - if (!entity) > - return ctrls->count; > + if (!entity) { > + ctrls->error_idx = ctrls->count; > + return ret; > + } > > for (i = 0; i < ctrls->count; i++) { > __uvc_find_control(entity, ctrls->controls[i].id, &mapping, > &ctrl_found, 0); > - if (uvc_control == ctrl_found) > - return i; > + if (err_control == ctrl_found) > + break; > } > + ctrls->error_idx = i; I think this line should be moved after the next check. > + > + /* We could not find the control that failed. */ > + if (i == ctrls->count) > + return ret; > > - return ctrls->count; > + if (uvc_ctrl_is_inactive(chain, err_control, mapping)) > + return -EACCES; > + > + return ret; > } > > int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback, > @@ -1679,8 +1704,8 @@ int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback, > uvc_ctrl_send_events(handle, ctrls->controls, ctrls->count); > done: > if (ret < 0 && ctrls) > - ctrls->error_idx = uvc_ctrl_find_ctrlidx(entity, ctrls, > - err_ctrl); > + ret = uvc_ctrl_commit_error(chain, entity, ctrls, err_ctrl, > + ret); > mutex_unlock(&chain->ctrl_mutex); > return ret; > } -- Regards, Laurent Pinchart