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Is DDR_SDRAM_CFG_3[ECC_FIX_EN] used?

Question asked by Tracy Smith on Sep 12, 2018

ECC fixing enable.
The DDR controller supports ECC fixing in memory. In this mode, the DDR controller will automatically fix
any detected single-bit errors by issuing a new transaction to read the address with the failing bit,
correcting the bit, and writing the data back to memory. The single-bit error will still be counted in the
ERR_SBE register for this case, but the controller will automatically fix the error. Note that during the
'read back', the single-bit error will not be double counted in the ERR_SBE register. In addition, the DDR
controller will periodically issue a read to memory at the interval defined by ECC_SCRUB_INT. If a
single-bit error is detected during a periodic read, it will be fixed. In this case, the error will be reported as
an SSBE in the ERR_SBE register. If a multi-bit eror is detected, then it will be reported in the
ERR_DETECT register. Also note that if a subsequent single-bit error is detected at the same address
while a first error is being fixed, then the second error will not be reported. Also, after a first SBE is
detected, no other SBEs will be fixed until the first SBE has been fixed in memory.This bit should only be
set if DDR_SDRAM_CFG[ECC_EN] is also set.
NOTE: Scrubbing cannot be enabled until after the controller has cleared
DDR_SDRAM_CFG_2[D_INIT].
0b - ECC scrubbing is disabled.
1b - ECC scrubbing is enabled.

 

When and where does this mode get selected by the Linux kernel and/or controller for SDRAM ECC correction?

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