diff options
Diffstat (limited to 'drivers/mtd/nand/gpmi-nand/gpmi-lib.c')
| -rw-r--r-- | drivers/mtd/nand/gpmi-nand/gpmi-lib.c | 18 |
1 files changed, 14 insertions, 4 deletions
diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c index 7f680420bfa..7db6555ed3b 100644 --- a/drivers/mtd/nand/gpmi-nand/gpmi-lib.c +++ b/drivers/mtd/nand/gpmi-nand/gpmi-lib.c @@ -69,17 +69,19 @@ static int clear_poll_bit(void __iomem *addr, u32 mask) * [1] enable the module. * [2] reset the module. * - * In most of the cases, it's ok. But there is a hardware bug in the BCH block. + * In most of the cases, it's ok. + * But in MX23, there is a hardware bug in the BCH block (see erratum #2847). * If you try to soft reset the BCH block, it becomes unusable until * the next hard reset. This case occurs in the NAND boot mode. When the board * boots by NAND, the ROM of the chip will initialize the BCH blocks itself. * So If the driver tries to reset the BCH again, the BCH will not work anymore. - * You will see a DMA timeout in this case. + * You will see a DMA timeout in this case. The bug has been fixed + * in the following chips, such as MX28. * * To avoid this bug, just add a new parameter `just_enable` for * the mxs_reset_block(), and rewrite it here. */ -int gpmi_reset_block(void __iomem *reset_addr, bool just_enable) +static int gpmi_reset_block(void __iomem *reset_addr, bool just_enable) { int ret; int timeout = 0x400; @@ -206,7 +208,15 @@ int bch_set_geometry(struct gpmi_nand_data *this) if (ret) goto err_out; - ret = gpmi_reset_block(r->bch_regs, true); + /* + * Due to erratum #2847 of the MX23, the BCH cannot be soft reset on this + * chip, otherwise it will lock up. So we skip resetting BCH on the MX23. + * On the other hand, the MX28 needs the reset, because one case has been + * seen where the BCH produced ECC errors constantly after 10000 + * consecutive reboots. The latter case has not been seen on the MX23 yet, + * still we don't know if it could happen there as well. + */ + ret = gpmi_reset_block(r->bch_regs, GPMI_IS_MX23(this)); if (ret) goto err_out; |