[U-Boot] [PATCH V2] i.MX: fsl_esdhc: allow use with cache enabled.

[Stefano Babic <sbabic@denx.de>]

On 15/05/2012 14:58, Dirk Behme wrote:
> On 09.05.2012 07:45, Stefano Babic wrote:
>> On 09/05/2012 01:31, Eric Nelson wrote:
>>> Thanks Andy,
>>>
>>> On 05/08/2012 03:59 PM, Andy Fleming wrote:
>>>>> --- a/drivers/mmc/fsl_esdhc.c
>>>>> +++ b/drivers/mmc/fsl_esdhc.c
>>>>> @@ -190,6 +190,10 @@ static int esdhc_setup_data(struct mmc *mmc,
>>>>> struct mmc_data *data)
>>>>>                 esdhc_clrsetbits32(&regs->wml, WML_RD_WML_MASK,
>>>>> wml_value);
>>>>>                 esdhc_write32(&regs->dsaddr, (u32)data->dest);
>>>>>         } else {
>>>>> +               flush_dcache_range((ulong)data->src,
>>>>> +                                  (ulong)data->src+data->blocks
>>>>> +                                        *data->blocksize);
>>>>> +
>>>>
>>>> This still won't work. I don't believe this is implemented at all on
>>>> the FSL PowerPC parts that use this controller.
>>>>
>>>> At the very least, it needs to be protected by an ifdef.
>>>>
>>> It seems more generally useful to implement a PowerPC cache layer
>>> than to instrument each driver that supports cache.
>>
>> Some PowerPC (MPC86xx,  arch/powerpc/cpu/mpc86xx/cache.S) have this
>> layer, some other not. This driver is used by MPC85xx and
>> flush_dcache_range is not implemented. The reason is that this SOC  uses
>> its internal snooping mechanism and does not need to explicitely flush
>> the buffers in the drivers.
>>
>> The problem with an #ifdef is that it is not very generic - we should
>> add some #if (defined(CONFIG_MX51) || defined(CONFIG_MX53) || ...
>> and update the driver for each new SOCs. I think also that maybe the
>> best way is to add an empty flush_dcache_range() to the MPC85xx, maybe
>> as weak function.
> 
> You might have noticed that I'm looking through my list of open patches.
> So: Any news regarding V3 of this patch? ;)

This is my turn to look back if there are some news. Has anyone taken a
look at it ?

Best regards,
Stefano Babic

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