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=-16.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 5141DC433C1 for ; Thu, 25 Mar 2021 13:55:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 19CA261A21 for ; Thu, 25 Mar 2021 13:55:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230516AbhCYNzH (ORCPT ); Thu, 25 Mar 2021 09:55:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43280 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230242AbhCYNyl (ORCPT ); Thu, 25 Mar 2021 09:54:41 -0400 Received: from mail-io1-xd2a.google.com (mail-io1-xd2a.google.com [IPv6:2607:f8b0:4864:20::d2a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id AF584C06174A for ; Thu, 25 Mar 2021 06:54:41 -0700 (PDT) Received: by mail-io1-xd2a.google.com with SMTP id x16so2009188iob.1 for ; Thu, 25 Mar 2021 06:54:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=RAEOlYgpnnIYtnpihZtbBWp/TA6l4Ck/OBKwCqfJMX4=; b=U9ApAVqWbo+VbJJpaUguYJQm3e60DFIMBmd8EJ3uFVw58OCUV6UomksLLO3Mve1j3t f7sxIKgGcuF54pHvwQJCfyE3ppJW944sO6Z6M0AQcSLS2C9DJ+nfynLpz/GlSv7RAPUg nbtRS3s0YX9ojeTNH1sfftfe53B4HXwMRDWTU= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=RAEOlYgpnnIYtnpihZtbBWp/TA6l4Ck/OBKwCqfJMX4=; b=IpARdqsvr8eV9SLOaujkKRdSztHH9oJKNzqwqlQ7JoILrtRToSsPEjbun0exffhqf9 CuJjBLPmxzYp1C0zeN5u4JNmBZ7BMGoWgoFM5b2LcrVPW4VWFTvQNeftM2Ww21ivrytT 6HOe4jHzH/FILLRfPhXkzKWUDBm0lA3PfhrHOk/GheLl8U87TU22qXItn39lAdm9UnSe qad2zsulic71SSFGknC0jlcFIJHKZ2bZUJt1KvEzEd8Z74XfpOJetz7AFrm337kNOXdm QCbXz7w5F769nTFdfmwL/MgfeascyRV1fEHq59ZanqZY8nJW5XaBjSGl/5rm6q8uaqNX Zc3w== X-Gm-Message-State: AOAM533u1aTnfEQhj1YHsmhwJR1jWkGAvp+qLRk5k0jgT2YlRQZ02U+J Hq5HaAvGneI45bzB0BcnXNh10hN3D0Ew8A== X-Google-Smtp-Source: ABdhPJwkZfmFRwbQ6795Ekb1yesTrvmWbjtaj/SRx4nNiCin9iSoA10+G/pMb5LSeRG6Flz9LMEAvA== X-Received: by 2002:a05:6638:2711:: with SMTP id m17mr7719458jav.115.1616680480971; Thu, 25 Mar 2021 06:54:40 -0700 (PDT) Received: from mail-il1-f182.google.com (mail-il1-f182.google.com. [209.85.166.182]) by smtp.gmail.com with ESMTPSA id g16sm2348673ilk.22.2021.03.25.06.54.40 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 25 Mar 2021 06:54:40 -0700 (PDT) Received: by mail-il1-f182.google.com with SMTP id j11so2139194ilu.13 for ; Thu, 25 Mar 2021 06:54:40 -0700 (PDT) X-Received: by 2002:a05:6e02:2182:: with SMTP id j2mr7073912ila.89.1616680479497; Thu, 25 Mar 2021 06:54:39 -0700 (PDT) MIME-Version: 1.0 References: <347cdb4a-19a2-98ce-580f-5aba4abfb2fc@xs4all.nl> <35f1fa6e-a498-9217-5359-82b58dec61f6@xs4all.nl> In-Reply-To: <35f1fa6e-a498-9217-5359-82b58dec61f6@xs4all.nl> From: Ricardo Ribalda Date: Thu, 25 Mar 2021 14:54:28 +0100 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] uvcvideo: improve error handling in uvc_query_ctrl() To: Hans Verkuil Cc: Ricardo Ribalda Delgado , Linux Media Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org hi Hans On Thu, Mar 25, 2021 at 1:18 PM Hans Verkuil wrote: > > On 23/03/2021 16:25, Ricardo Ribalda Delgado wrote: > > Hi Hans > > > > Thanks for the patch. I like how uvc is ending :) > > > > On Mon, Mar 22, 2021 at 1:09 PM Hans Verkuil wrote: > >> > >> - 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. > >> > >> Signed-off-by: Hans Verkuil > >> --- > >> Ricardo, this too can be added to the uvc series. > >> --- > >> drivers/media/usb/uvc/uvc_video.c | 44 +++++++++++++++++-------------- > >> 1 file changed, 24 insertions(+), 20 deletions(-) > >> > >> diff --git a/drivers/media/usb/uvc/uvc_video.c b/drivers/media/usb/uvc/uvc_video.c > >> index b63c073ec30e..3f461bb4eeb9 100644 > >> --- a/drivers/media/usb/uvc/uvc_video.c > >> +++ b/drivers/media/usb/uvc/uvc_video.c > >> @@ -68,7 +68,7 @@ int uvc_query_ctrl(struct uvc_device *dev, u8 query, u8 unit, > >> u8 intfnum, u8 cs, void *data, u16 size) > >> { > >> int ret; > >> - u8 error; > >> + u8 error = 0; > >> u8 tmp; > >> > >> ret = __uvc_query_ctrl(dev, query, unit, intfnum, cs, data, size, > >> @@ -76,35 +76,39 @@ 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); > >> + ret = ret < 0 ? ret : -EPIPE; > >> > >> - if (ret != -EPIPE) > >> - return ret; > >> - > >> - tmp = *(u8 *)data; > >> + if (ret == -EPIPE) { > >> + 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); > >> + ret = __uvc_query_ctrl(dev, UVC_GET_CUR, 0, intfnum, > >> + UVC_VC_REQUEST_ERROR_CODE_CONTROL, data, 1, > >> + UVC_CTRL_CONTROL_TIMEOUT); > >> > >> - error = *(u8 *)data; > >> - *(u8 *)data = tmp; > >> + if (ret == 1) > >> + error = *(u8 *)data; > >> + *(u8 *)data = tmp; > >> + if (ret != 1) > >> + ret = ret < 0 ? ret : -EPIPE; > >> + } > >> > >> - if (ret != 1) > >> - return ret < 0 ? ret : -EPIPE; > >> + if (error) > >> + dev_dbg(&dev->udev->dev, > >> + "Failed to query (%s) UVC control %u on unit %u: got error %u.\n", > >> + uvc_query_name(query), cs, unit, error); > >> + else > >> + 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); > > > > If __uvc_query_ctrl and UVC_VC_REQUEST_ERROR_CODE_CONTROL failed, > > error is 0. And I think that you want to show a dev_err in that case. > > Maybe we can initialize error to 7 ? > > I'm confused, if error == 0, then it does show dev_err. My bad. Ignore the message. Can we write it as ?: if (!error) { dev_dbg(&dev->udev->dev, "Failed to query (%s) UVC control %u on unit %u: got error %u.\n", uvc_query_name(query), cs, unit, error); return ret; } 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); > > > > > > >> > >> - uvc_dbg(dev, CONTROL, "Control error %u\n", error); > >> + if (!error) > >> + return ret; > > I think we do not want these two lines (read next comment) > >> > >> 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 */ > > > > Maybe we want a dev_dbg if the error code is unknown and return ret? > > Make sense. > > Regards, > > Hans -- Ricardo Ribalda