[U-Boot] [PATCH] spi: cadence_qspi_apb: Improve indirect write transaction

[Marek Vasut]

On 10/18/2016 10:23 AM, Vignesh R wrote:
> 
> 
> On Thursday 06 October 2016 04:49 PM, Vignesh R wrote:
>> If the write transaction size(write_bytes) is not a multiple of word
>> length, then issue word length writes till the we reach the dangling
>> bytes. On the final write, issue byte by byte write to complete the
>> transaction. This marginally improves write throughput when performing
>> random sized writes to the flash.
>>
>> Signed-off-by: Vignesh R <vigneshr at ti.com>
>> ---
> 
> Gentle ping... Any comments?
> 
>>
>> Tested on K2G GP EVM.
>>
>>  drivers/spi/cadence_qspi_apb.c | 10 ++++++++--
>>  1 file changed, 8 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/spi/cadence_qspi_apb.c b/drivers/spi/cadence_qspi_apb.c
>> index e285d3c1e761..4b891f227243 100644
>> --- a/drivers/spi/cadence_qspi_apb.c
>> +++ b/drivers/spi/cadence_qspi_apb.c
>> @@ -752,10 +752,16 @@ int cadence_qspi_apb_indirect_write_execute(struct cadence_spi_platdata *plat,
>>  	while (remaining > 0) {
>>  		write_bytes = remaining > page_size ? page_size : remaining;
>>  		/* Handle non-4-byte aligned access to avoid data abort. */
>> -		if (((uintptr_t)txbuf % 4) || (write_bytes % 4))
>> +		if ((uintptr_t)txbuf % 4) {
>>  			writesb(plat->ahbbase, txbuf, write_bytes);
>> -		else
>> +		} else {
>>  			writesl(plat->ahbbase, txbuf, write_bytes >> 2);
>> +			if (write_bytes % 4) {
>> +				writesb(plat->ahbbase,
>> +					txbuf + rounddown(write_bytes, 4),
>> +					write_bytes % 4);
>> +			}

You can probably pull this block from the else branch.

>> +		}
>>  
>>  		ret = wait_for_bit("QSPI", plat->regbase + CQSPI_REG_SDRAMLEVEL,
>>  				   CQSPI_REG_SDRAMLEVEL_WR_MASK <<
>>
> 


-- 
Best regards,
Marek Vasut