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 52BB9C48BDF for ; Thu, 10 Jun 2021 17:14:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 37776613E9 for ; Thu, 10 Jun 2021 17:14:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230080AbhFJRQV (ORCPT ); Thu, 10 Jun 2021 13:16:21 -0400 Received: from perceval.ideasonboard.com ([213.167.242.64]:48590 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229802AbhFJRQS (ORCPT ); Thu, 10 Jun 2021 13:16:18 -0400 Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id C8EE78D4; Thu, 10 Jun 2021 19:14:20 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1623345261; bh=W3SG8UnrOuR0iNr7YMC6xV0NHhWpG2qC0B18el8uGRY=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=CWs4pucu7yHlt13WsWWDMESpaBZ19pWRiJViN5CTYioV6Vd2b3vucesFsxQyScg39 dhQnGZNEVeIJ97MQCJWfeq2ue5YQ1lE8JTnke1B6AwLK9EXU76wCxmVKDS1GYcPd+M s7KkN5GmI10Pd+7CpCwlFgeF+F/K6x7NDeCy3Kw4= Date: Thu, 10 Jun 2021 20:14:02 +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, Hans Verkuil Subject: Re: [PATCH v9 20/22] uvcvideo: improve error handling in uvc_query_ctrl() Message-ID: References: <20210326095840.364424-1-ribalda@chromium.org> <20210326095840.364424-21-ribalda@chromium.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210326095840.364424-21-ribalda@chromium.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Ricardo and Hans, Thank you for the patch. On Fri, Mar 26, 2021 at 10:58:38AM +0100, Ricardo Ribalda wrote: > From: Hans Verkuil > > - If __uvc_query_ctrl() failed with a non-EPIPE error, then > report that with dev_err. If an error code is obtained, then > report that with dev_dbg. > > - For error 2 (Wrong state) return -EACCES instead of -EILSEQ. > EACCES is a much more appropriate error code. EILSEQ will return > "Invalid or incomplete multibyte or wide character." in strerror(), > which is a *very* confusing message. I would have split the commit in two. > Signed-off-by: Hans Verkuil > --- > > I have changed a bit the patch from the original version. > > drivers/media/usb/uvc/uvc_video.c | 38 +++++++++++++++++-------------- > 1 file changed, 21 insertions(+), 17 deletions(-) > > diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c > index b63c073ec30e..1c3a94d91724 100644 > --- a/drivers/media/usb/uvc/uvc_video.c > +++ b/drivers/media/usb/uvc/uvc_video.c > @@ -76,35 +76,31 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit, > if (likely(ret == size)) > return 0; > > - dev_dbg(&dev->udev->dev, > - "Failed to query (%s) UVC control %u on unit %u: %d (exp. %u).\n", > - uvc_query_name(query), cs, unit, ret, size); > - > - if (ret != -EPIPE) > - return ret; > + if (ret < 0 && ret != -EPIPE) > + goto err; > > + // reuse data[0] for request the error code. C-style comments please. s/for request/to request/ > tmp = *(u8 *)data; > - > ret = __uvc_query_ctrl(dev, UVC_GET_CUR, 0, intfnum, > UVC_VC_REQUEST_ERROR_CODE_CONTROL, data, 1, > UVC_CTRL_CONTROL_TIMEOUT); > - No need to drop the blank lines. > error = *(u8 *)data; > *(u8 *)data = tmp; > > - if (ret != 1) > - return ret < 0 ? ret : -EPIPE; > + if (ret != 1) { > + ret = ret < 0 ? ret : -EPIPE; > + goto err; > + } > > - uvc_dbg(dev, CONTROL, "Control error %u\n", error); > + dev_dbg(&dev->udev->dev, Why not uvc_dbg ? > + "Failed to query (%s) UVC control %u on unit %u: got error %u.\n", > + uvc_query_name(query), cs, unit, error); > > switch (error) { > - case 0: > - /* Cannot happen - we received a STALL */ > - return -EPIPE; > case 1: /* Not ready */ > return -EBUSY; > case 2: /* Wrong state */ > - return -EILSEQ; > + return -EACCES; > case 3: /* Power */ > return -EREMOTE; > case 4: /* Out of range */ > @@ -120,10 +116,18 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit, > case 8: /* Invalid value within range */ > return -EINVAL; > default: /* reserved or unknown */ > - break; > + dev_err(&dev->udev->dev, > + "Failed to query (%s) UVC control %u on unit %u: got error %u.\n", > + uvc_query_name(query), cs, unit, error); when debugging is enabled, this will print the error message a second time, it's not very nice. > + return -EPIPE; > } > > - return -EPIPE; > +err: > + dev_err(&dev->udev->dev, > + "Failed to query (%s) UVC control %u on unit %u: %d (exp. %u).\n", > + uvc_query_name(query), cs, unit, ret, size); > + > + return ret; > } > > static void uvc_fixup_video_ctrl(struct uvc_streaming *stream, -- Regards, Laurent Pinchart