lkml.org 
[lkml]   [2018]   [Jul]   [3]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH 2/2] misc: sram: enable clock before registering regions
From
Date
On 07/03/2018 02:47 PM, Johan Hovold wrote:
> On Tue, Jul 03, 2018 at 01:23:30PM +0300, Vladimir Zapolskiy wrote:
>> Hi Johan,
>>
>> On 07/03/2018 01:05 PM, Johan Hovold wrote:
>>> Make sure to enable the clock before registering regions and exporting
>>> partitions to user space at which point we must be prepared for I/O.
>>>
>>> Fixes: ee895ccdf776 ("misc: sram: fix enabled clock leak on error path")
>>> Cc: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
>>> Signed-off-by: Johan Hovold <johan@kernel.org>
>>
>> thank you for the change, however please note that the identified commit
>> for the fix is incorrect one apparently.
>>
>> In my opinion the proper tag contents would be
>>
>> Fixes: b4c3fcb3c71f ("misc: sram: extend usage of reserved partitions")
>>
>> I hope you agree to it, also I would suggest to swap the changes in
>> the series.
>
> No, I think I used the right commit in the Fixes tag as that was the
> commit which moved the clock enable to after the memory-region
> registration (at which point the memory could potentially be accessed).

I was confused by the moved sram_reserve_regions() call, which was added
way later.

Allright, if it is assumed that gen_pool_get() interface requires only
a registered memory pool provider device, and it does, then there is
another kind of a problem, a SRAM/genpool consumer may not get access
to a valid region in SRAM before the latter is added to the SRAM pool
in sram_probe().

Instantly I don't know how to solve the issue above, it may require
a change to lib/genalloc.c to request a registration of genpool device
driver, but then such a change solves the problem identified by you
as well.

For your change as a proper (partial?) fix:

Reviewed-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>

--
Best wishes,
Vladimir

\
 
 \ /
  Last update: 2018-07-03 14:30    [W:0.104 / U:0.160 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site