From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from perceval.ideasonboard.com ([95.142.166.194]:59422 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757004Ab2IMKQt (ORCPT ); Thu, 13 Sep 2012 06:16:49 -0400 From: Laurent Pinchart To: Hans Verkuil Cc: linux-media@vger.kernel.org, Hans Verkuil Subject: Re: [RFCv2 API PATCH 05/28] DocBook: bus_info can no longer be empty. Date: Thu, 13 Sep 2012 03:24:53 +0200 Message-ID: <2833220.AbcIRhH3Bk@avalon> In-Reply-To: <7d0e5a9425253ece02bb57adc9413a5558200f2d.1347023744.git.hans.verkuil@cisco.com> References: <1347024568-32602-1-git-send-email-hverkuil@xs4all.nl> <7d0e5a9425253ece02bb57adc9413a5558200f2d.1347023744.git.hans.verkuil@cisco.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-media-owner@vger.kernel.org List-ID: Hi Hans, Thanks for the patch. On Friday 07 September 2012 15:29:05 Hans Verkuil wrote: > From: Hans Verkuil > > During the 2012 Media Workshop it was decided that bus_info as returned > by VIDIOC_QUERYCAP can no longer be empty. It should be a unique identifier, > and empty strings are obviously not unique. > > Signed-off-by: Hans Verkuil > --- > Documentation/DocBook/media/v4l/vidioc-querycap.xml | 14 ++++++++++---- > 1 file changed, 10 insertions(+), 4 deletions(-) > > diff --git a/Documentation/DocBook/media/v4l/vidioc-querycap.xml > b/Documentation/DocBook/media/v4l/vidioc-querycap.xml index > f33dd74..d5b1248 100644 > --- a/Documentation/DocBook/media/v4l/vidioc-querycap.xml > +++ b/Documentation/DocBook/media/v4l/vidioc-querycap.xml > @@ -90,11 +90,17 @@ ambiguities. > __u8 > bus_info[32] > Location of the device in the system, a > -NUL-terminated ASCII string. For example: "PCI Slot 4". This > +NUL-terminated ASCII string. For example: "PCI:0000:05:06.0". This > information is intended for users, to distinguish multiple > -identical devices. If no such information is available the field may > -simply count the devices controlled by the driver, or contain the > -empty string (bus_info[0] = 0). > +identical devices. If no such information is available the field must > +simply count the devices controlled by the driver ("vivi-000"). The > bus_info > +must start with "PCI:" for PCI boards, "PCIe:" for PCI Express boards, > +"usb-" for USB devices, "I2C:" for i2c devices, "ISA:" for ISA devices and > +"parport" for parallel port devices. What about being a bit more precise than that ? We could specify what API drivers must use to fill the bus_info field. For instance, for USB devices, usb_make_path() is currently used by most drivers (which, by the way, doesn't return a string that starts with "USB:"). > +For devices without a bus it should start with the driver name, optionally > +followed by "-" and an index if multiple instances of the device as > possible. > +Many platform devices can have only one instance, so in that case bus_info > +is identical to the driver field. > > __u32 -- Regards, Laurent Pinchart