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

[Scott Wood <scottwood@freescale.com>]

On Wed, 2014-04-02 at 08:34 +0530, Prabhakar Kushwaha wrote:
> 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.

It wasn't mentioned in this patch submission...

> 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.

But this patch seems to assume the bug hasn't been fixed -- it still has
a progress meter, and it still breaks the SPI read into 8K chunks (not
sure if that part would change as part of the fix).

-Scott