[PATCH 4/7] dmaengine: at_xdmac: adapt perid for mem2mem operations

Tudor.Ambarus at microchip.com Tudor.Ambarus at microchip.com
Wed Sep 23 01:35:35 EDT 2020


On 9/23/20 8:30 AM, Tudor Ambarus - M18064 wrote:
> On 9/14/20 5:09 PM, Eugen Hristev wrote:
>> The PERID in the CC register for mem2mem operations must match an unused
>> PERID.
>> The PERID field is 7 bits, but the selected value is 0x3f.
>> On later products we can have more reserved PERIDs for actual peripherals,
>> thus this needs to be increased to maximum size.
>> Changing the value to 0x7f, which is the maximum for 7 bits field.
>>
> 
> Maybe it is worth to explain that for memory-to-memory transfers, PERID
> should be set to an unused peripheral ID, and the maximum value seems the
> safest. Anyway with or without this addressed, one can add:
> 

:) I somehow misread your commit message, you already described that, it's fine.

> Reviewed-by: Tudor Ambarus <tudor.ambarus at microchip.com>
> 
>> Signed-off-by: Eugen Hristev <eugen.hristev at microchip.com>
>> ---
>>  drivers/dma/at_xdmac.c | 6 +++---
>>  1 file changed, 3 insertions(+), 3 deletions(-)
>>


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