Chris Ball wrote:
> Hi David,
> 
> On Thu, Sep 30, 2010 at 08:03:14PM -0700, Philip Rakity wrote:
>> From: Philip Rakity <[email protected]>
>> Date: Thu, 30 Sep 2010 15:34:24 -0700
>> Subject: [PATCH] sdhci: adjust sd 3.0 host controller spec clock divider
>>
>> The sd 3.0 host spec does not require the clock divider to be a power of 2.
>>
>> Signed-off-by: Philip Rakity <[email protected]>
>> ---
>>  drivers/mmc/host/sdhci.c |    8 +++-----
>>  1 files changed, 3 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index 96c7f60..73a94fe 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -1003,14 +1003,12 @@ static void sdhci_set_clock(struct sdhci_host *host, 
>> unsigned int clock)
>>              goto out;
>>  
>>      if (host->version >= SDHCI_SPEC_300) {
>> -            /* Version 3.00 divisors must be a multiple of 2. */
>>              if (host->max_clk <= clock)
>>                      div = 1;
>>              else {
>> -                    for (div = 2; div < SDHCI_MAX_DIV_SPEC_300; div += 2) {
>> -                            if ((host->max_clk / div) <= clock)
>> -                                    break;
>> -                    }
>> +                    div = host->max_clk/clock;
>> +                    if (host->max_clk % clock)
>> +                            div++;
>>              }
>>      } else {
>>              /* Version 2.00 divisors must be a power of 2. */
>> -- 
> 
> Would you mind reviewing this, please?  I don't have access to the 3.0
> spec.

NAK.  The divisors for 3.00 controllers must be a multiple of two (the
register value N gives a divisor of 2N).

David
-- 
David Vrabel, Senior Software Engineer, Drivers
CSR, Churchill House, Cambridge Business Park,  Tel: +44 (0)1223 692562
Cowley Road, Cambridge, CB4 0WZ                 http://www.csr.com/


Member of the CSR plc group of companies. CSR plc registered in England and 
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Business Park, Cowley Road, Cambridge, CB4 0WZ, United Kingdom
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