[U-Boot] [PATCH 7/10] driver/mtd/spi:Read 8KB data chunk during u-boot load in SPL

[Prabhakar Kushwaha <prabhakar@freescale.com>]

On 4/2/2014 3:32 AM, Scott Wood wrote:
> On Mon, 2014-03-31 at 15:34 +0530, Prabhakar Kushwaha wrote:
>> SPI driver perform its operation(read/write) on 64KB buffer chunk for data
>> greater than 64KB. This buffer chunk is allocated from system heap.
>>
>> During SPL boot, 768KB of data is read from SPI flash.
>> Here, heap size may not be sufficient enough to full-fill 64KB buffer
>> requirement of SPI driver. So break down u-boot read operation at 8KB of chunk.
>>
>> Also, fix a warning i.e. "unused variable buf" during CONFIG_FSL_CORENET
>>
>> Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
>> ---
>>   drivers/mtd/spi/fsl_espi_spl.c |   15 ++++++++++++---
>>   1 file changed, 12 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/mtd/spi/fsl_espi_spl.c b/drivers/mtd/spi/fsl_espi_spl.c
>> index e5ac79b..a55d741 100644
>> --- a/drivers/mtd/spi/fsl_espi_spl.c
>> +++ b/drivers/mtd/spi/fsl_espi_spl.c
>> @@ -20,8 +20,10 @@
>>   void spi_boot(void)
>>   {
>>   	void (*uboot)(void) __noreturn;
>> -	u32 offset, code_len;
>> +	u32 offset, code_len, copy_len = 0;
>> +#ifndef CONFIG_FSL_CORENET
>>   	unsigned char *buf = NULL;
>> +#endif
>>   	struct spi_flash *flash;
>>   
>>   	flash = spi_flash_probe(CONFIG_ENV_SPI_BUS, CONFIG_ENV_SPI_CS,
>> @@ -56,8 +58,15 @@ void spi_boot(void)
>>   	code_len = code_len - CONFIG_SPL_MAX_SIZE;
>>   #endif
>>   	/* copy code to DDR */
>> -	spi_flash_read(flash, offset, code_len,
>> -		       (void *)CONFIG_SYS_SPI_FLASH_U_BOOT_DST);
>> +	printf("Loading second stage boot loader ");
>> +	while (copy_len <= code_len) {
>> +		spi_flash_read(flash, offset + copy_len, 0x2000,
>> +			       (void *)(CONFIG_SYS_SPI_FLASH_U_BOOT_DST
>> +			       + copy_len));
>> +		copy_len = copy_len + 0x2000;
>> +		putc('.');
>> +	}
> How long does this take?  If it's long enough to warrant a progress
> meter, that ought to be fixed first.
>
>
It take 20 sec to boot.  it is long enough.  This issue has already been 
reported.

Problem is reading 1 MB from SPI flash.  It take almost 20s in on u-boot 
prompt from any boot.

I agree, we should first fix it.
But This patch should not be stopped to get apply because of issue 
somewhere else. That issue can be fixed separately in other patch.

Regards,
Prabhakar