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 01C061E1308; Tue, 1 Jul 2025 18:42:07 +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=1751395329; cv=none; b=HFpU9UOqAaCmAPNN9lGr+81pSVYOgkFNMwKk9Ucx2LdlWDMe1Z80n2msx4GCUYJKMEfZ5PWG0gWXpFCDyumRtw1kFqANkQlyNILaCl9c3wXVJ8qz9rqLDfTA4JvyKdybue79XOg5bo9N/I/gsEm0KbAOXhb4+wH9A+IqHdU0R0w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751395329; c=relaxed/simple; bh=hTAKzDSpqOWH6oNEG3mvFlGYvEadh1l19viyvjMn+f0=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=CS9L3iA0/ZxYrwkvQAEbYZ9R+Ski7ZkLfdSrrFNEmnI2T/R2YGf0td5mgHD7I8i41YvwRJi3nAuoBFFjGrCjkuqsOGpLRwAbDsBh0UWBx+LxxRacIN+mHaMRMkZnJiuzXsN3sfGnOVEUeU8ywR6PU6zJMUIpGQPA3y8Zkbssn1s= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (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=GuXyeAzV; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (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="GuXyeAzV" Received: from pendragon.ideasonboard.com (81-175-209-231.bb.dnainternet.fi [81.175.209.231]) by perceval.ideasonboard.com (Postfix) with UTF8SMTPSA id EAA397E0; Tue, 1 Jul 2025 20:41:37 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1751395298; bh=hTAKzDSpqOWH6oNEG3mvFlGYvEadh1l19viyvjMn+f0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=GuXyeAzVKf3P1IdPNwV8CpzzersBhulaJMIFMkaQt5M5OtfxfpgIbW2mXRtd17BAy mP9RcT4H4Ia5BJHh5q8xzCLBpax1aOPVkccanh8vNAE3Kab6GKNAmjIllSwp3JqTlU 6W8jUuWL5rZgdsVJNaorS55jMGMnVHMi4LjFSY7c= Date: Tue, 1 Jul 2025 21:41:34 +0300 From: Laurent Pinchart To: Desnes Nunes Cc: Ricardo Ribalda , hansg@kernel.org, linux-media@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] media: uvcvideo: avoid variable shadowing in uvc_ctrl_cleanup_fh Message-ID: <20250701184134.GC1936@pendragon.ideasonboard.com> References: <20250701145240.105959-1-desnesn@redhat.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 Content-Transfer-Encoding: 8bit In-Reply-To: On Tue, Jul 01, 2025 at 02:20:53PM -0300, Desnes Nunes wrote: > On Tue, Jul 1, 2025 at 1:48 PM Ricardo Ribalda wrote: > > On Tue, 1 Jul 2025 at 16:59, Desnes Nunes wrote: > > > > > > This avoids a variable loop shadowing occurring between the local loop > > > iterating through the uvc_entity's controls and the global one going > > > through the pending async controls of the file handle > > > > > > Fixes: 10acb9101355 ("media: uvcvideo: Increase/decrease the PM counter per IOCTL") > > If you add a fixes you need to add > > Cc: stable@kernel.org > > Thanks for letting me know > > > Reviewed-by: Ricardo Ribalda > > > Signed-off-by: Desnes Nunes > > > --- > > > drivers/media/usb/uvc/uvc_ctrl.c | 3 +-- > > > 1 file changed, 1 insertion(+), 2 deletions(-) > > > > > > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c > > > index 44b6513c5264..91cc874da798 100644 > > > --- a/drivers/media/usb/uvc/uvc_ctrl.c > > > +++ b/drivers/media/usb/uvc/uvc_ctrl.c > > > @@ -3260,7 +3260,6 @@ int uvc_ctrl_init_device(struct uvc_device *dev) > > > void uvc_ctrl_cleanup_fh(struct uvc_fh *handle) > > > { > > > struct uvc_entity *entity; > > > - int i; > > > > > > guard(mutex)(&handle->chain->ctrl_mutex); > > > > > > @@ -3278,7 +3277,7 @@ void uvc_ctrl_cleanup_fh(struct uvc_fh *handle) > > > if (!WARN_ON(handle->pending_async_ctrls)) > > > return; > > > > > > - for (i = 0; i < handle->pending_async_ctrls; i++) > > > > nitpick: I would have called the variable i, not j. For me j usually > > means nested loop. But up to you > > Noted - I used a different variable name because I wanted to > differentiate the loops. Variable declaration in the loop statement is relatively new in the kernel, so there's no consensus yet (to my knowledge) on clear coding styles, but I would have simply used the same variable name in both loops, with two separate declarations: diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c index 303b7509ec47..6b9486749c3f 100644 --- a/drivers/media/usb/uvc/uvc_ctrl.c +++ b/drivers/media/usb/uvc/uvc_ctrl.c @@ -3299,7 +3299,6 @@ int uvc_ctrl_init_device(struct uvc_device *dev) void uvc_ctrl_cleanup_fh(struct uvc_fh *handle) { struct uvc_entity *entity; - int i; guard(mutex)(&handle->chain->ctrl_mutex); @@ -3317,7 +3316,7 @@ void uvc_ctrl_cleanup_fh(struct uvc_fh *handle) if (!WARN_ON(handle->pending_async_ctrls)) return; - for (i = 0; i < handle->pending_async_ctrls; i++) + for (unsigned int i = 0; i < handle->pending_async_ctrls; i++) uvc_pm_put(handle->stream->dev); } Is there a downside to this ? > > I am also not against your first version with a different commit message. > > Third time's a charm then! > > Will send a v2 with the first version having this commit message. > > Thanks for the review Ricardo, -- Regards, Laurent Pinchart