Hi Simon, On Sun, Jun 9, 2013 at 9:36 PM, Jagan Teki <[email protected]> wrote: > Hi Simon, > > On Sun, Jun 9, 2013 at 7:43 PM, Simon Glass <[email protected]> wrote: >> Hi Jagan, >> >> On Sat, Jun 8, 2013 at 7:44 AM, Jagan Teki <[email protected]> wrote: >>> >>> Hi Simon, >>> >>> On Sat, Jun 8, 2013 at 8:02 PM, Simon Glass <[email protected]> wrote: >>> > Hi Jagan, >>> > >>> > On Sat, Jun 8, 2013 at 1:32 AM, Jagan Teki <[email protected]> >>> > wrote: >>> >> >>> >> Hi Simon, >>> >> >>> >> Please let know your comments. >>> >> >>> >> I have changed the logic, but removed spi_flash_cmd_poll_bit() use >>> >> poll code on spi_flash_cmd_wait_ready() >>> >> as no other call for spi_flash_cmd_poll_bit() this. >>> >> >>> >> And also for read_status the check_status i assigned as 0,earlier it >>> >> has direct 0 (w/o check_status variable). >>> >> >>> >> To add the support for flag status on the same code, i define this >>> >> check_status. >>> >> I don't see any coding functionality change for now, compared to >>> >> before. >>> > >>> > >>> > This is not the right patch, but in one of them you remove >>> > spi_flash_cmd_poll_bit(), so that it no longer works the same way. You >>> > will >>> > get lots of individual SPI transactions on the bus instead of a single >>> > one >>> > that reads the status byte continuously. >>> >>> I couldn't understand you clearly. >>> >>> Earlier all erase/write they were calling spi_flash_cmd_wait_ready >>> with flash, timeout values. >>> spi_flash_cmd_wait_ready() is intern call to spi_flash_cmd_poll_bit() >>> with CMD_READ_STATUS and STATUS_WIP. >>> >>> In my changes I have removed spi_flash_cmd_poll_bit() as there is no >>> other caller except spi_flash_cmd_wait_ready() >>> so all polling stuff on spi_flash_cmd_wait_ready() means, still >>> erase/program can call spi_flash_cmd_wait_ready() with >>> flash, timeout and CMD_READ_STATUS and STAUS_WIP were use directly >>> used on spi_flash_cmd_wait_ready() instead >>> of passing through spi_flash_cmd_poll_bit(). >>> >>> Any wrong here, please comment. >> >> >> You have changed the implementation of spi_flash_cmd_wait_ready() so that >> instead of polling for the bit within a single SPI transaction (CS staying >> asserted) you are now doing multiple transactions. >> >> The old code for spi_flash_cmd_wait_ready() ended up with an algorithm like >> this, when you look inside the nested functions: >> >> spi_claim_bus(spi); >> ret = spi_xfer(spi, cmd_len * 8, cmd, NULL, SPI_XFER_BEGIN); >> do { >> ret = spi_xfer(spi, 8, NULL, &status, 0); >> ... >> } >> spi_xfer(spi, 0, NULL, NULL, SPI_XFER_END); >> spi_release_bus(spi); >> >> The new code is: >> >> do { >> spi_claim_bus(spi); >> ret = spi_xfer(spi, cmd_len * 8, cmd, NULL, SPI_XFER_BEGIN); >> ret = spi_xfer(spi, data_len * 8, data_out, data_in, SPI_XFER_END); >> spi_release_bus(spi); >> ... >> } while (...) >> >> >> Can you see the difference? The bus clain and SPI_XFER_BEGIN/END is now >> inside the loop. > > Understand, i thought as we do _END transfer in old code as well. > It could be fine to go with using common function as it will do _BEGIN and > _END. > > What could be the problem you see if we do _BEGIN and _END on loop...? > >> >> Is there a reason why this change is needed? Does updating the bank address >> not work with the old code? > > It doesn't effect with banking. > > Thanks, > Jagan. > >> >> It is find to move the spi_flash_cmd_poll_bit() function into >> spi_flash_cmd_wait_ready() - I am not worried about that. I am only worried >> about your change of algorithm as above. >> >> Regards, >> Simon >> >>> >>> >>> Thanks, >>> Jagan. >>> >>> > >>> > Do we need to change this? >>> > >>> > >>> >> >>> >> >>> >> -- >>> >> Thanks, >>> >> Jagan. >>> >> >>> >> On Fri, May 31, 2013 at 6:22 PM, Jagannadha Sutradharudu Teki >>> >> <[email protected]> wrote: >>> >> > Flag status register polling is required for micron 512Mb flash >>> >> > devices onwards, for performing erase/program operations. >>> >> > >>> >> > Like polling for WIP(Write-In-Progress) bit in read status register, >>> >> > spi_flash_cmd_wait_ready will poll for PEC(Program-Erase-Control) >>> >> > bit in flag status register. >>> >> > >>> >> > Signed-off-by: Jagannadha Sutradharudu Teki <[email protected]> >>> >> > --- >>> >> > Changes for v2: >>> >> > - none >>> >> > >>> >> > drivers/mtd/spi/spi_flash.c | 15 ++++++++++++--- >>> >> > drivers/mtd/spi/spi_flash_internal.h | 3 +++ >>> >> > 2 files changed, 15 insertions(+), 3 deletions(-) >>> >> > >>> >> > diff --git a/drivers/mtd/spi/spi_flash.c >>> >> > b/drivers/mtd/spi/spi_flash.c >>> >> > index 527423d..8cd2988 100644 >>> >> > --- a/drivers/mtd/spi/spi_flash.c >>> >> > +++ b/drivers/mtd/spi/spi_flash.c >>> >> > @@ -195,25 +195,34 @@ int spi_flash_cmd_wait_ready(struct spi_flash >>> >> > *flash, unsigned long timeout) >>> >> > unsigned long timebase; >>> >> > int ret; >>> >> > u8 status; >>> >> > + u8 check_status = 0x0; >>> >> > u8 poll_bit = STATUS_WIP; >>> >> > u8 cmd = CMD_READ_STATUS; >>> >> > >>> >> > + if ((flash->idcode0 == 0x20) && >>> >> > + (flash->size >= SPI_FLASH_512MB_STMIC)) { >>> >> > + poll_bit = STATUS_PEC; >>> >> > + check_status = poll_bit; >>> >> > + cmd = CMD_FLAG_STATUS; >>> >> > + } >>> >> > + >>> >> > timebase = get_timer(0); >>> >> > do { >>> >> > WATCHDOG_RESET(); >>> >> > >>> >> > ret = spi_flash_read_common(flash, &cmd, 1, &status, >>> >> > 1); >>> >> > if (ret < 0) { >>> >> > - debug("SF: fail to read read status >>> >> > register\n"); >>> >> > + debug("SF: fail to read %s status >>> >> > register\n", >>> >> > + cmd == CMD_READ_STATUS ? "read" : >>> >> > "flag"); >>> >> > return ret; >>> >> > } >>> >> > >>> >> > - if ((status & poll_bit) == 0) >>> >> > + if ((status & poll_bit) == check_status) >>> >> > break; >>> >> > >>> >> > } while (get_timer(timebase) < timeout); >>> >> > >>> >> > - if ((status & poll_bit) == 0) >>> >> > + if ((status & poll_bit) == check_status) >>> >> > return 0; >>> >> > >>> >> > /* Timed out */ >>> >> > diff --git a/drivers/mtd/spi/spi_flash_internal.h >>> >> > b/drivers/mtd/spi/spi_flash_internal.h >>> >> > index ac4530f..cb7a505 100644 >>> >> > --- a/drivers/mtd/spi/spi_flash_internal.h >>> >> > +++ b/drivers/mtd/spi/spi_flash_internal.h >>> >> > @@ -13,6 +13,7 @@ >>> >> > #define SPI_FLASH_SECTOR_ERASE_TIMEOUT (10 * CONFIG_SYS_HZ) >>> >> > >>> >> > #define SPI_FLASH_16MB_BOUN 0x1000000 >>> >> > +#define SPI_FLASH_512MB_STMIC 0x4000000 >>> >> > >>> >> > /* Common commands */ >>> >> > #define CMD_READ_ID 0x9f >>> >> > @@ -24,6 +25,7 @@ >>> >> > #define CMD_PAGE_PROGRAM 0x02 >>> >> > #define CMD_WRITE_DISABLE 0x04 >>> >> > #define CMD_READ_STATUS 0x05 >>> >> > +#define CMD_FLAG_STATUS 0x70 >>> >> > #define CMD_WRITE_ENABLE 0x06 >>> >> > #define CMD_ERASE_4K 0x20 >>> >> > #define CMD_ERASE_32K 0x52 >>> >> > @@ -38,6 +40,7 @@ >>> >> > >>> >> > /* Common status */ >>> >> > #define STATUS_WIP 0x01 >>> >> > +#define STATUS_PEC 0x80 >>> >> > >>> >> > /* Send a single-byte command to the device and read the response */ >>> >> > int spi_flash_cmd(struct spi_slave *spi, u8 cmd, void *response, >>> >> > size_t >>> >> > len); >>> >> > -- >>> >> > 1.8.3 >>> >> >>
May be I will explore much for this, update the changes later. and i will remains the code as before as of now. Do you have any more comments on this series. I will going to send v3 and planning to apply. -- Thanks, Jagan. _______________________________________________ U-Boot mailing list [email protected] http://lists.denx.de/mailman/listinfo/u-boot
