linux-kernel - Re: Looking for good references for ARM driver development

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <546E600F.8020704@free.fr>
Date:	Thu, 20 Nov 2014 22:41:35 +0100
From:	Mason <mpeg.blue@...e.fr>
To:	Victor Ascroft <victorascroft@...il.com>
CC:	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	devicetree@...r.kernel.org
Subject: Re: Looking for good references for ARM driver development

On 19/11/2014 17:57, Victor Ascroft wrote:

> On 11/19/2014 06:20 PM, Mason wrote:
> 
>> Are there more recent technical references, as good as LDD3, that
>> cover "modern" aspects of kernel development?
> 
> The LDD3 is one of the best there is. A fourth edition is supposed
> to come out sometime next year.
> http://www.amazon.com/Linux-Device-Drivers-Jessica-McKellar/dp/1449371612

That's the best news I've heard this week!
Hope Jonathan gets well and lives happily ever after.

>> How do I "leave device registration for the system infrastructure"?
>> Where should I put that code?
>> Is it a good idea to separate device registration and driver registration
>> in the case of a SoC, where the device is embedded in the SoC and is not
>> "hot-plugged" (or anything-plugged for that matter, it's just "there").
> 
> For understanding this you need to understand how the platform infrastructure
> works and why is it used.
> http://lwn.net/Articles/448499/
> http://lwn.net/Articles/448502/
> and go through some of the relevant drivers.

More of Jon's (great) work ;-)
Will definitely read these articles carefully.

>> 3) Why is the function used to "destroy a platform device" named
>> platform_device_put? Why put?
>> Put on a list of things to destroy at a later time?
> 
> This should be more clear once you go through LDD3.

I'm coming up empty.
AFAICT, it's unrelated to the _put_user* family of functions.
I see that it has something to do with ref count decrement.
[more reading...]
Something about kref.
https://lwn.net/Articles/336224/

They mention "put" but not *why* it's called "put".
Is it related to Dijkstra's P and V for semaphores?
https://cs.nyu.edu/~yap/classes/os/resources/origin_of_PV.html
Still confused...

Regards.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/