linux-kernel - Re: [PATCH] clk: clk-divider: fix divisor

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>] [day] [month] [year] [list]

Message-ID: <52CA807E.8020100@imgtec.com>
Date:	Mon, 6 Jan 2014 10:07:58 +0000
From:	James Hogan <james.hogan@...tec.com>
To:	Mike Turquette <mturquette@...aro.org>
CC:	<linux-kernel@...r.kernel.org>, Rajendra Nayak <rnayak@...com>,
	<linux-arm-kernel@...ts.infradead.org>, <stable@...r.kernel.org>
Subject: Re: [PATCH] clk: clk-divider: fix divisor > 255 bug

On 03/01/14 04:15, Mike Turquette wrote:
> Quoting James Hogan (2013-12-16 02:41:38)
>> Commit 6d9252bd9a4bb (clk: Add support for power of two type dividers)
>> merged in v3.6 added the _get_val function to convert a divisor value to
>> a register field value depending on the flags. However it used the type
>> u8 for the div field, causing divisors larger than 255 to be masked
>> and the resultant clock rate to be too high.
>>
>> E.g. in my case an 11bit divider was supposed to divide 24.576 MHz down
>> to 32.768KHz. The divisor was correctly calculated as 750 (0x2ee). This
>> was masked to 238 (0xee) resulting in a frequency of 103.26KHz.
>>
>> Signed-off-by: James Hogan <james.hogan@...tec.com>
> 
> Taken into clk-next. Thanks for the fix!

Thanks Mike, is there any chance of getting this into v3.13, or is it
too late?

Cheers
James

>> Cc: Rajendra Nayak <rnayak@...com>
>> Cc: Mike Turquette <mturquette@...aro.org>
>> Cc: linux-arm-kernel@...ts.infradead.org
>> Cc: stable@...r.kernel.org
>> ---
>> Since this bug was introduced in 3.6, it probably should by applied to
>> stable 3.10 and 3.12.
>> ---
>>  drivers/clk/clk-divider.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
>> index 8d3009e44fba..5543b7df8e16 100644
>> --- a/drivers/clk/clk-divider.c
>> +++ b/drivers/clk/clk-divider.c
>> @@ -87,7 +87,7 @@ static unsigned int _get_table_val(const struct clk_div_table *table,
>>         return 0;
>>  }
>>  
>> -static unsigned int _get_val(struct clk_divider *divider, u8 div)
>> +static unsigned int _get_val(struct clk_divider *divider, unsigned int div)
>>  {
>>         if (divider->flags & CLK_DIVIDER_ONE_BASED)
>>                 return div;
>> -- 
>> 1.8.1.2
>>
>>


Download attachment "signature.asc" of type "application/pgp-signature" (837 bytes)