oppo R821 write flash failed..


here is log

Phone must be off with battery inside.
Please insert USB cable now…
Detected : MTK USB Port (COM11)
Phone detected…Please wait
Sending DA agent, please wait…
BBCHIP MT6572_S00
EMMC: (28Gb+4096Mb) HYNIX 0x2058494e5948
EMMC FW VERSION: 16:00:00:00:00:00:00:00
BOOT STYLE : EMMC BOOT
Detecting high speed port, wait……
If driver not installed, install high speed port driver.
Detected : DA USB VCOM Port (COM12)
Warning, flashing preloader disabled!
If you change android version, preloader must be flashed.
Starting flash.
Detected partitions count: 21
FORMAT EMMC FLASH : BEGIN:0x3bf40000 – LEN:0x7e00000
FORMAT EMMC FLASH : BEGIN:0x43d40000 – LEN:0x40000000
Download firmware to flash now…
Error: S_DA_SDMMC_WRITE_FAILED
After flash this firmware need to perform some aditional steps
1.Reinsert battery, keep VOL- and power on untill phone will come in factory mode
2.Select line EMMC, and after press home button.
3.Wait untill phone will restart and will stuck on logo(leave for 1 min in this stage).
4.If phone not power on, reinsert battery and perform direct unlock.
If repair fail, please contact us or report in forum to provide help.

note:
device condition HANG ON OPPO logo
custamer say after download one app set be stuck on oppo logo.