From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753274AbbHVCAU (ORCPT ); Fri, 21 Aug 2015 22:00:20 -0400 Received: from cnc.isely.net ([75.149.91.89]:33445 "EHLO cnc.isely.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752136AbbHVCAT (ORCPT ); Fri, 21 Aug 2015 22:00:19 -0400 X-Greylist: delayed 303 seconds by postgrey-1.27 at vger.kernel.org; Fri, 21 Aug 2015 22:00:18 EDT Date: Fri, 21 Aug 2015 20:55:14 -0500 (CDT) From: Mike Isely Reply-To: Mike Isely at pobox To: Ricardo Ribalda Delgado cc: Mauro Carvalho Chehab , Laurent Pinchart , Hans Verkuil , Steven Toth , Sakari Ailus , Vincent Palatin , linux-media@vger.kernel.org, Linux Kernel Mailing List , Mike Isely at pobox Subject: Re: [PATCH v2 07/10] media/usb/pvrusb2: Support for V4L2_CTRL_WHICH_DEF_VAL In-Reply-To: <1440163169-18047-8-git-send-email-ricardo.ribalda@gmail.com> Message-ID: References: <1440163169-18047-1-git-send-email-ricardo.ribalda@gmail.com> <1440163169-18047-8-git-send-email-ricardo.ribalda@gmail.com> User-Agent: Alpine 2.02 (DEB 1266 2009-07-14) Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The code you've added is carefully checking the return pointer from pvr2_hdw_get_ctrl_v4l() yet the original code did not operate this way. The result is that now there's this "unbalanced" effect where it appears that the validity of the pvr2_ctrl instance is only checked on one side of the if-statement. I would recommend instead to elevate the call to pvr2_hdw_get_ctrl_v4l() out of the if-statement - since in both cases it's being called the same way both times. Then do the validity check in that one spot and that simplifies the if-statement all the way down to choosing between pvr2_ctrl_get_value() vs pvr2_ctrl_get_def(). It's not a correctness comment; what you have should work fine. So I'm ack'ing this in any case: Acked-By: Mike Isely But you can do the above pretty easily & safely, and simplify it a bit further. -Mike On Fri, 21 Aug 2015, Ricardo Ribalda Delgado wrote: > This driver does not use the control infrastructure. > Add support for the new field which on structure > v4l2_ext_controls > > Signed-off-by: Ricardo Ribalda Delgado > --- > drivers/media/usb/pvrusb2/pvrusb2-v4l2.c | 17 ++++++++++++++++- > 1 file changed, 16 insertions(+), 1 deletion(-) > > diff --git a/drivers/media/usb/pvrusb2/pvrusb2-v4l2.c b/drivers/media/usb/pvrusb2/pvrusb2-v4l2.c > index 1c5f85bf7ed4..43b2f2214798 100644 > --- a/drivers/media/usb/pvrusb2/pvrusb2-v4l2.c > +++ b/drivers/media/usb/pvrusb2/pvrusb2-v4l2.c > @@ -628,6 +628,7 @@ static int pvr2_g_ext_ctrls(struct file *file, void *priv, > struct pvr2_v4l2_fh *fh = file->private_data; > struct pvr2_hdw *hdw = fh->channel.mc_head->hdw; > struct v4l2_ext_control *ctrl; > + struct pvr2_ctrl *cptr; > unsigned int idx; > int val; > int ret; > @@ -635,8 +636,18 @@ static int pvr2_g_ext_ctrls(struct file *file, void *priv, > ret = 0; > for (idx = 0; idx < ctls->count; idx++) { > ctrl = ctls->controls + idx; > - ret = pvr2_ctrl_get_value( > + if (ctls->which == V4L2_CTRL_WHICH_DEF_VAL) { > + cptr = pvr2_hdw_get_ctrl_v4l(hdw, ctrl->id); > + if (cptr) > + pvr2_ctrl_get_def(cptr, &val); > + else > + ret = -EINVAL; > + > + > + } else > + ret = pvr2_ctrl_get_value( > pvr2_hdw_get_ctrl_v4l(hdw, ctrl->id), &val); > + > if (ret) { > ctls->error_idx = idx; > return ret; > @@ -658,6 +669,10 @@ static int pvr2_s_ext_ctrls(struct file *file, void *priv, > unsigned int idx; > int ret; > > + /* Default value cannot be changed */ > + if (ctls->which == V4L2_CTRL_WHICH_DEF_VAL) > + return -EINVAL; > + > ret = 0; > for (idx = 0; idx < ctls->count; idx++) { > ctrl = ctls->controls + idx; > -- Mike Isely isely @ isely (dot) net PGP: 03 54 43 4D 75 E5 CC 92 71 16 01 E2 B5 F5 C1 E8