Hi Jagan, On Tue, Apr 23, 2013 at 2:15 PM, Jagan Teki <[email protected]> wrote: > Hi Simon, > > On Wed, Apr 24, 2013 at 2:43 AM, Simon Glass <[email protected]> wrote: >> Hi Jagan, >> >> On Tue, Apr 23, 2013 at 2:01 PM, Jagan Teki <[email protected]> wrote: >>> Hi Simon, >>> >>> On Wed, Apr 24, 2013 at 2:20 AM, Simon Glass <[email protected]> wrote: >>>> Hi Jagan, >>>> >>>> On Tue, Apr 23, 2013 at 1:44 PM, Jagan Teki <[email protected]> >>>> wrote: >>>>> Hi Simon, >>>>> >>>>> On Mon, Mar 11, 2013 at 9:38 PM, Simon Glass <[email protected]> wrote: >>>>>> Some SPI flash controllers (e.g. Intel ICH) have a limit on the number of >>>>>> bytes that can be in a write transaction. Support this by breaking the >>>>>> writes into multiple transactions. >>>>>> >>>>>> Signed-off-by: Simon Glass <[email protected]> >>>>>> --- >>>>>> Changes in v2: None >>>>>> >>>>>> drivers/mtd/spi/spi_flash.c | 10 ++++++++-- >>>>>> 1 file changed, 8 insertions(+), 2 deletions(-) >>>>>> >>>>>> diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c >>>>>> index 17f3d3c..b82011d 100644 >>>>>> --- a/drivers/mtd/spi/spi_flash.c >>>>>> +++ b/drivers/mtd/spi/spi_flash.c >>>>>> @@ -87,6 +87,9 @@ int spi_flash_cmd_write_multi(struct spi_flash *flash, >>>>>> u32 offset, >>>>>> for (actual = 0; actual < len; actual += chunk_len) { >>>>>> chunk_len = min(len - actual, page_size - byte_addr); >>>>>> >>>>>> + if (flash->spi->max_write_size) >>>>>> + chunk_len = min(chunk_len, >>>>>> flash->spi->max_write_size); >>>>>> + >>>>>> cmd[1] = page_addr >> 8; >>>>>> cmd[2] = page_addr; >>>>>> cmd[3] = byte_addr; >>>>>> @@ -111,8 +114,11 @@ int spi_flash_cmd_write_multi(struct spi_flash >>>>>> *flash, u32 offset, >>>>>> if (ret) >>>>>> break; >>>>>> >>>>>> - page_addr++; >>>>>> - byte_addr = 0; >>>>>> + byte_addr += chunk_len; >>>>>> + if (byte_addr == page_size) { >>>>>> + page_addr++; >>>>>> + byte_addr = 0; >>>>>> + } >>>>> >>>>> Does this change required to handle < page_size writes, means if the >>>>> user is giving an offset other than >>>>> multiples of page_sizes? >>>> >>>> I'm not quite sure what you are saying, but let me try to response. >>>> >>>> I believe what should happen is that byte_addr should become aligned >>>> to the page_size after the first transfer, and from then on it should >>>> start at 0 for each page. >>>> >>>> Are you seeing a problem? >>> >>> My question,what if this change doesn't have.? >>> Can't I able to write data starts from unaligned page_sizes? >> >> It should work fine - I did in fact find a problem in the driver in >> this case, which I fixed. Let me know if you see any problem. > > Means this change is for proper handling of write data starts from > unaligned page_sizes, is it?
Not really - it was designed to handle the case where the driver cannot write a whole page at once. The Intel ICH peripheral has this problem. I believe that writing starting from unaligned page sizes worked OK before this change. Regards, Simon > > Thanks, > Jagan. > >> >> Regards, >> Simon >> >>> >>> Thanks, >>> Jagan. >>> >>>> >>>> Regards, >>>> Simon >>>> >>>>> >>>>> Thanks, >>>>> Jagan. _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
