Re: [PATCH 2/5] VT binding: Add sysfs support

[Antonino A. Daplas]

Greg KH wrote:
> On Sat, Jun 10, 2006 at 08:38:18AM +0800, Antonino A. Daplas wrote:
>> Greg KH wrote:
>>> On Fri, Jun 09, 2006 at 04:39:51PM +0800, Antonino A. Daplas wrote:
>>>> Add sysfs attributes for binding and unbinding VT console drivers. The
>>>> attributes are located in /sys/class/tty/console and are namely:
>>>>
>>>>     A. backend - list registered drivers in the following format:
>>>>
>>>>     "I C: Description"
>>> No, this violates the "one value per file" issue with sysfs.  How do you
>>> know you will not overflow the buffer passed to you?
>> I was wondering about this. I just want a way to show what are the currently
>> loaded drivers, so it's a read-only attribute.  It's using snprintf (though
>> I haven't added a check for possible overflows, should be a 2-liner). Maximum
>> number of lines is 16, and there are examples of this rule-breakage in the
>> current sysfs tree.
>>
>> /sys/class/usb_host/usb_hostx/device/pools
> 
> Ah, thanks for pointing this out.  Those files should go to debugfs,
> they do NOT belong in sysfs at all.
> 
>> Yes, none are valid excuses.  Anyway, what would be the best way? I was
>> considering creating another class for vt_console, but that would entail
>> the creation of a new device major number just for this.
> 
> No, you don't need a major to create a new class in sysfs at all.  Look
> at usb_host for an example of that :)

Aha, I see it now. Yes, this is exactly what I need. Thanks for the tip.

> Ok, I also read the 0/5 in this series which describes this in detail,
> sorry for not seeing that (hint, cc: everyone on the series that one
> too, so they get a bit of detail in the future.)
> 

Sorry about that, slipped my mind.

Tony

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