Micron provides READ RETRY support via the ONFI vendor-specific
parameter block (to indicate how many read-retry modes are available)
and the ONFI {GET,SET}_FEATURES commands with a vendor-specific feature
address (to support reading/switching the current read-retry mode).
The recommended sequence is as follows:
1. Perform PAGE_READ operation
2. If no ECC error, we are done
3. Run SET_FEATURES with feature address 89h, mode 1
4. Retry PAGE_READ operation
5. If ECC error and there are remaining supported modes, increment the
mode and return to step 3. Otherwise, this is a true ECC error.
6. Run SET_FEATURES with feature address 89h, mode 0, to return to the
default state.
This patch implements the chip->setup_read_retry() callback for
Micron and fills in the chip->read_retries.
Tested on Micron MT29F32G08CBADA, which supports 8 read-retry modes.
The Micron vendor-specific table was checked against the datasheets for
the following Micron NAND:
Needs retry Cell-type Part number Vendor revision Byte 180
----------- --------- ---------------- --------------- ------------
No SLC MT29F16G08ABABA 1 Reserved (0)
No MLC MT29F32G08CBABA 1 Reserved (0)
No SLC MT29F1G08AACWP 1 0
Yes MLC MT29F32G08CBADA 1 08h
Yes MLC MT29F64G08CBABA 2 08h
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Acked-by: Huang Shijie <b32955@freescale.com>
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