From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BFD3A9476; Tue, 22 Apr 2025 23:05:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745363119; cv=none; b=ROdf0u4D7sl5HNxBPCWVeYH5jA7Bx4dRxZMModgL8oypGX3wWedhR0rUs0YDVDLrnMnhKuow7G/GGnjbMXoDgDuTBZeaPISmGF+IlCXPVZ2G96gy0XXe4Tktl9GE+Pu5Ss2pRxqEor+GrWS7WtTE0nZ5yO4VPJk9Y2dMb0gyZJI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745363119; c=relaxed/simple; bh=FL5En/dLy4zeOnwuuG6OIWOr8qeBBzE0k/ehSxsVGAw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=F+amArNU6bnm1xjFNGJCxfWhV1//wi2oYmbS9HSL26zD6lBo0fR+3EPaDdDL/upBlnR/CTi7UUPhgS6XK1ziyelWT/kCMk2XB7f8SMxJVqUDnSz/9X/pZWvxEa0ugix6+tF4XHaNaWehcHxZM+M5sf8ERgJTw4cMkMfkzsi7Pfk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=eOPSGLbo; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="eOPSGLbo" Received: from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi [81.175.209.231]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 2181816A; Wed, 23 Apr 2025 01:05:15 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1745363115; bh=FL5En/dLy4zeOnwuuG6OIWOr8qeBBzE0k/ehSxsVGAw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=eOPSGLbo2IiCZaUTW4iE14SYcLgGCbtVbE6eBd95bNDqyMkXdifWW8omJ//X0hKfN ugUn6eauz8CSwpmwgXvklVds5CyZU6a/CWaU7K7JbzoHJamjaa+z8byJgkhmk+trvf G9j30riMdCE45dzR8gLgbOM+2fSlCYUcNY+OBOZQ= Date: Wed, 23 Apr 2025 02:05:13 +0300 From: Laurent Pinchart To: Ricardo Ribalda Cc: Hans de Goede , Mauro Carvalho Chehab , Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Douglas Anderson Subject: Re: [PATCH v3 1/2] media: uvcvideo: Fix deferred probing error Message-ID: <20250422230513.GX17813@pendragon.ideasonboard.com> References: <20250313-uvc-eprobedefer-v3-0-a1d312708eef@chromium.org> <20250313-uvc-eprobedefer-v3-1-a1d312708eef@chromium.org> <20250422180630.GJ17813@pendragon.ideasonboard.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: On Wed, Apr 23, 2025 at 06:50:10AM +0800, Ricardo Ribalda wrote: > On Wed, 23 Apr 2025 at 02:06, Laurent Pinchart wrote: > > On Thu, Mar 13, 2025 at 12:20:39PM +0000, Ricardo Ribalda wrote: > > > uvc_gpio_parse() can return -EPROBE_DEFER when the GPIOs it depends on > > > have not yet been probed. This return code should be propagated to the > > > caller of uvc_probe() to ensure that probing is retried when the required > > > GPIOs become available. > > > > > > Currently, this error code is incorrectly converted to -ENODEV, > > > causing some internal cameras to be ignored. > > > > > > This commit fixes this issue by propagating the -EPROBE_DEFER error. > > > > > > Cc: stable@vger.kernel.org > > > Fixes: 2886477ff987 ("media: uvcvideo: Implement UVC_EXT_GPIO_UNIT") > > > Reviewed-by: Douglas Anderson > > > Signed-off-by: Ricardo Ribalda > > > --- > > > drivers/media/usb/uvc/uvc_driver.c | 27 +++++++++++++++++++-------- > > > 1 file changed, 19 insertions(+), 8 deletions(-) > > > > > > diff --git a/drivers/media/usb/uvc/uvc_driver.c b/drivers/media/usb/uvc/uvc_driver.c > > > index deadbcea5e227c832976fd176c7cdbfd7809c608..e966bdb9239f345fd157588ebdad2b3ebe45168d 100644 > > > --- a/drivers/media/usb/uvc/uvc_driver.c > > > +++ b/drivers/media/usb/uvc/uvc_driver.c > > > @@ -2231,13 +2231,16 @@ static int uvc_probe(struct usb_interface *intf, > > > #endif > > > > > > /* Parse the Video Class control descriptor. */ > > > - if (uvc_parse_control(dev) < 0) { > > > + ret = uvc_parse_control(dev); > > > + if (ret < 0) { > > > + ret = -ENODEV; > > > > Why do you set ret to -ENODEV here... > > > > > uvc_dbg(dev, PROBE, "Unable to parse UVC descriptors\n"); > > > goto error; > > > } > > > > > > /* Parse the associated GPIOs. */ > > > - if (uvc_gpio_parse(dev) < 0) { > > > + ret = uvc_gpio_parse(dev); > > > + if (ret < 0) { > > > uvc_dbg(dev, PROBE, "Unable to parse UVC GPIOs\n"); > > > goto error; > > > } > > > @@ -2263,24 +2266,32 @@ static int uvc_probe(struct usb_interface *intf, > > > } > > > > > > /* Register the V4L2 device. */ > > > - if (v4l2_device_register(&intf->dev, &dev->vdev) < 0) > > > + ret = v4l2_device_register(&intf->dev, &dev->vdev); > > > + if (ret < 0) > > > > ... but not here ? The code below is also not very consistant. > > For all the "external" functions I was looking into populating their > error code to probe(). Other drivers (check vivid for example) do > exactly this. > > There is more value in returning the real cause of the error (ENOMEM, > EINVAL) that the plain ENODEV. Yes, I got that, my question was why you override the return value of e.g. uvc_parse_control() or uvc_scan_device() with -ENODEV, but not for e.g. uvc_gpio_parse() or v4l2_device_register(). There's no explanation in the commit message regarding why they're treated differently. > > > goto error; > > > > > > /* Scan the device for video chains. */ > > > - if (uvc_scan_device(dev) < 0) > > > + if (uvc_scan_device(dev) < 0) { > > > + ret = -ENODEV; > > > goto error; > > > + } > > > > > > /* Initialize controls. */ > > > - if (uvc_ctrl_init_device(dev) < 0) > > > + if (uvc_ctrl_init_device(dev) < 0) { > > > + ret = -ENODEV; > > > goto error; > > > + } > > > > > > /* Register video device nodes. */ > > > - if (uvc_register_chains(dev) < 0) > > > + if (uvc_register_chains(dev) < 0) { > > > + ret = -ENODEV; > > > goto error; > > > + } > > > > > > #ifdef CONFIG_MEDIA_CONTROLLER > > > /* Register the media device node */ > > > - if (media_device_register(&dev->mdev) < 0) > > > + ret = media_device_register(&dev->mdev); > > > + if (ret < 0) > > > goto error; > > > #endif > > > /* Save our data pointer in the interface data. */ > > > @@ -2314,7 +2325,7 @@ static int uvc_probe(struct usb_interface *intf, > > > error: > > > uvc_unregister_video(dev); > > > kref_put(&dev->ref, uvc_delete); > > > - return -ENODEV; > > > + return ret; > > > } > > > > > > static void uvc_disconnect(struct usb_interface *intf) -- Regards, Laurent Pinchart