IFC-1.1.0 uses 28nm techenology for SRAM. This tech has known limitaion for
SRAM i.e. "byte select" is not supported. Hence Read Modify Write is
implemented in IFC for any "system side write" into sram buffer. Reading an
uninitialized memory results in ECC Error from sram wrapper.
Hence we must initialize/prefill SRAM buffer by any data before writing
anything in SRAM from system side. To initialize SRAM user can use "READID"
NAND command with read bytes equal to SRAM size. It will be a one time
activity post boot.
Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Acked-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
New NAND controllers can perform read/write via HW engines which don't expose
OOB data in their DMA mode. To reflect this, we should rework the nand_chip /
nand_ecc_ctrl interfaces that assume that drivers will always read/write OOB
data in the nand_chip.oob_poi buffer. A better interface includes a boolean
argument that explicitly tells the callee when OOB data is requested by the
calling layer (for reading/writing to/from nand_chip.oob_poi).
This patch adds the 'oob_required' parameter to each relevant {read,write}_page
interface; all 'oob_required' parameters are left unused for now. The next
patch will set the parameter properly in the nand_base.c callers, and follow-up
patches will make use of 'oob_required' in some of the callee functions.
Note that currently, there is no harm in ignoring the 'oob_required' parameter
and *always* utilizing nand_chip.oob_poi, but there can be
performance/complexity/design benefits from avoiding filling oob_poi in the
common case. I will try to implement this for some drivers which can be ported
easily.
Note: I couldn't compile-test all of these easily, as some had ARCH
dependencies.
[dwmw2: Merge later 1/0 vs. true/false cleanup]
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Reviewed-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
Acked-by: Jiandong Zheng <jdzheng@broadcom.com>
Acked-by: Mike Dunn <mikedunn@newsguy.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
