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Date: Fri, 07 Sep 2012 22:00:33 +0200
From: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
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To: Hans Verkuil <hverkuil@xs4all.nl>
CC: linux-media@vger.kernel.org,
	Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
	Hans Verkuil <hans.verkuil@cisco.com>
Subject: Re: [RFCv2 API PATCH 05/28] DocBook: bus_info can no longer be empty.
References: <1347024568-32602-1-git-send-email-hverkuil@xs4all.nl> <7d0e5a9425253ece02bb57adc9413a5558200f2d.1347023744.git.hans.verkuil@cisco.com>
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On 09/07/2012 03:29 PM, Hans Verkuil wrote:
> From: Hans Verkuil<hans.verkuil@cisco.com>
> 
> 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<hans.verkuil@cisco.com>

Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>

> ---
>   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.</entry>
>   	<entry>__u8</entry>
>   	<entry><structfield>bus_info</structfield>[32]</entry>
>   	<entry>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 (<structfield>bus_info</structfield>[0] = 0).<!-- XXX pci_dev->slot_name example --></entry>
> +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.
> +For devices without a bus it should start with the driver name, optionally

Most, if not all, devices are on some sort of bus. What would be an example
of a device "without a bus" ?

Could we just be saying here "For other devices" instead of "For devices
without a bus", or something similar ?

> +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<structfield>driver</structfield>  field.</entry>
>   	</row>
>   	<row>
>   	<entry>__u32</entry>

--

Regards,
Sylwester