Re: [PATCH v7 2/2] mtd: rawnand: meson: add support for Amlogic NAND flash controller

On Mon, 10 Dec 2018 19:23:46 +0800
Liang Yang [off-list ref] wrote:

quoted

quoted

+			mtd->ecc_stats.failed++;
+			continue;
+		}
+		mtd->ecc_stats.corrected += ECC_ERR_CNT(*info);
+		bitflips = max_t(u32, bitflips, ECC_ERR_CNT(*info));
+	}  

Are you sure you handle correctly empty pages with bf?
  

if scramble is enable, i would say yes here.
when scramble is disabled, i am considering how to use the helper 
nand_check_erased_ecc_chunk, but it seems that i can't get the ecc
bytes which is caculated by ecc engine.by the way, nfc dma doesn't send 
out the ecc parity bytes.

Even if the ECC engine is disabled?

so i would suggest using scramble.

No, please don't force people to use the scrambler.

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+
+const void *
+meson_nand_op_get_dma_safe_output_buf(const struct nand_op_instr *instr)
+{
+	if (WARN_ON(instr->type != NAND_OP_DATA_OUT_INSTR))
+		return NULL;
+
+	if (virt_addr_valid(instr->ctx.data.buf.out) &&
+	    !object_is_on_stack(instr->ctx.data.buf.out))  

Can you please create helpers for that? I guess it will help removing
these checks once the core will have a DMA-safe approach.
  

I will use below definition:
#define BUFFER_IS_DMA_SAFE(x)	\
	(virt_addr_valid((x)) && (!object_is_on_stack((x))))

Is it ok?

Please define a function, not a macro.

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