It could happen (1 out of 100 times) that NAND did not start up correctly after warm rebooting, so we end up with various failures or DMA timed out due to a stalled BCH. When resetting BCH together with GPMI, the issue could not be observed anymore (after 10000+ reboots). We probably need the consistent state already before sending commands to NAND. This behaviour was observed in barebox and kernel, so I assume it affects U-Boot as well. I chose to keep the extra reset for BCH when changing the flash layout to be on the safe side.
Signed-off-by: Wolfram Sang <w.s...@pengutronix.de> --- Only compile tested. Test case was to repeatedly reboot into a simple userspace on a UBI volume. Either the bootloader failed to find its data or the kernel could not mount the UBI volume once in a while. (Yes, the kernel could not mount the UBI although it was itself loaded correctly from NAND. So, it is some set-up issue.) This was nasty to debug, so I thought I let you know... drivers/mtd/nand/mxs_nand.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/mtd/nand/mxs_nand.c b/drivers/mtd/nand/mxs_nand.c index 4701be8..e38e151 100644 --- a/drivers/mtd/nand/mxs_nand.c +++ b/drivers/mtd/nand/mxs_nand.c @@ -1058,6 +1058,8 @@ int mxs_nand_init(struct mxs_nand_info *info) { struct mxs_gpmi_regs *gpmi_regs = (struct mxs_gpmi_regs *)MXS_GPMI_BASE; + struct mxs_bch_regs *bch_regs = + (struct mxs_bch_regs *)MXS_BCH_BASE; int i = 0, j; info->desc = malloc(sizeof(struct mxs_dma_desc *) * @@ -1081,6 +1083,7 @@ int mxs_nand_init(struct mxs_nand_info *info) /* Reset the GPMI block. */ mxs_reset_block(&gpmi_regs->hw_gpmi_ctrl0_reg); + mxs_reset_block(&bch_regs->hw_bch_ctrl_reg); /* * Choose NAND mode, set IRQ polarity, disable write protection and -- 1.7.10.4 _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot