Re: [PATCH 0/3] ARM: OMAP2+: hwmod: RTC: Add lock and unlock hooks

[Tero Kristo <t-kristo@ti.com>]

On 07/14/2015 01:09 PM, Lokesh Vutla wrote:
> Hi,
> On Wednesday 10 June 2015 02:56 PM, Lokesh Vutla wrote:
>> Some IP blocks like RTC, needs an additional unlocking mechanism for
>> writing to its registers. This patch adds optional lock and unlock
>> function pointers to the IP block's hwmod data which gets executed
>> before and after writing into IP sysconfig register.
>> And also hook lock and unlock functions to AMx3xx, DRA7 RTC hwmod data,
>> so that sysconfig registers are updated properly.
> ping on this series.
>
> Thanks and regards,
> Lokesh

This looks kind of hackish to have the unlock + lock functionality copy 
pasted to both driver and hwmod.

It is also racy, as there is no locking in place to avoid concurrent 
access to the lock/unlock registers across hwmod+driver.

Can we avoid these issues somehow?

-Tero

>>
>> Tested on:
>> DRA7-evm: http://pastebin.ubuntu.com/11688889/
>> DRA72-evm: http://pastebin.ubuntu.com/11688901/
>> BeagleBoard-x15: http://pastebin.ubuntu.com/11688907/
>> BeagleBoneBlack: http://pastebin.ubuntu.com/11688923/
>> AM437x-gp-evm: http://pastebin.ubuntu.com/11689157/ (Used an out of tree patch to enable RTC)
>>
>> Lokesh Vutla (3):
>>    ARM: OMAP2+: hwmod: add support for lock and unlock hooks
>>    ARM: DRA: hwmod: RTC: Add lock and unlock functions
>>    ARM: AMx3xx: RTC: Add lock and unlock functions
>>
>>   arch/arm/mach-omap2/omap_hwmod.c                   | 13 ++++++
>>   arch/arm/mach-omap2/omap_hwmod.h                   |  6 +++
>>   .../mach-omap2/omap_hwmod_33xx_43xx_ipblock_data.c |  2 +
>>   arch/arm/mach-omap2/omap_hwmod_7xx_data.c          |  2 +
>>   arch/arm/mach-omap2/omap_hwmod_reset.c             | 47 ++++++++++++++++++++++
>>   5 files changed, 70 insertions(+)
>>
>