Revert "mtd: atmel_nand: optimize read/write buffer functions"
This reverts commit fb5427508a
.
The reason is that it breaks 16 bits NAND flash as it was reported by
Nikolaus Voss and confirmed by Eric Bénard.
Nicolas Ferre <nicolas.ferre@atmel.com> alco confirmed:
"After double checking with designers, I must admit that I misunderstood
the way of optimizing accesses to SMC. 16 bit nand is not so common
those days..."
Reported-by: Nikolaus Voss <n.voss@weinmann.de>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Cc: stable@kernel.org [3.1+]
This commit is contained in:
parent
1a30871fe6
commit
500823195d
1 changed files with 41 additions and 4 deletions
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@ -161,6 +161,37 @@ static int atmel_nand_device_ready(struct mtd_info *mtd)
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!!host->board->rdy_pin_active_low;
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!!host->board->rdy_pin_active_low;
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}
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}
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/*
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* Minimal-overhead PIO for data access.
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*/
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static void atmel_read_buf8(struct mtd_info *mtd, u8 *buf, int len)
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{
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struct nand_chip *nand_chip = mtd->priv;
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__raw_readsb(nand_chip->IO_ADDR_R, buf, len);
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}
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static void atmel_read_buf16(struct mtd_info *mtd, u8 *buf, int len)
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{
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struct nand_chip *nand_chip = mtd->priv;
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__raw_readsw(nand_chip->IO_ADDR_R, buf, len / 2);
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}
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static void atmel_write_buf8(struct mtd_info *mtd, const u8 *buf, int len)
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{
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struct nand_chip *nand_chip = mtd->priv;
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__raw_writesb(nand_chip->IO_ADDR_W, buf, len);
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}
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static void atmel_write_buf16(struct mtd_info *mtd, const u8 *buf, int len)
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{
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struct nand_chip *nand_chip = mtd->priv;
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__raw_writesw(nand_chip->IO_ADDR_W, buf, len / 2);
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}
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static void dma_complete_func(void *completion)
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static void dma_complete_func(void *completion)
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{
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{
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complete(completion);
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complete(completion);
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@ -235,27 +266,33 @@ static int atmel_nand_dma_op(struct mtd_info *mtd, void *buf, int len,
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static void atmel_read_buf(struct mtd_info *mtd, u8 *buf, int len)
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static void atmel_read_buf(struct mtd_info *mtd, u8 *buf, int len)
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{
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{
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struct nand_chip *chip = mtd->priv;
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struct nand_chip *chip = mtd->priv;
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struct atmel_nand_host *host = chip->priv;
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if (use_dma && len > mtd->oobsize)
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if (use_dma && len > mtd->oobsize)
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/* only use DMA for bigger than oob size: better performances */
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/* only use DMA for bigger than oob size: better performances */
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if (atmel_nand_dma_op(mtd, buf, len, 1) == 0)
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if (atmel_nand_dma_op(mtd, buf, len, 1) == 0)
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return;
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return;
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/* if no DMA operation possible, use PIO */
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if (host->board->bus_width_16)
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memcpy_fromio(buf, chip->IO_ADDR_R, len);
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atmel_read_buf16(mtd, buf, len);
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else
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atmel_read_buf8(mtd, buf, len);
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}
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}
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static void atmel_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
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static void atmel_write_buf(struct mtd_info *mtd, const u8 *buf, int len)
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{
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{
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struct nand_chip *chip = mtd->priv;
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struct nand_chip *chip = mtd->priv;
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struct atmel_nand_host *host = chip->priv;
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if (use_dma && len > mtd->oobsize)
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if (use_dma && len > mtd->oobsize)
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/* only use DMA for bigger than oob size: better performances */
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/* only use DMA for bigger than oob size: better performances */
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if (atmel_nand_dma_op(mtd, (void *)buf, len, 0) == 0)
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if (atmel_nand_dma_op(mtd, (void *)buf, len, 0) == 0)
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return;
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return;
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/* if no DMA operation possible, use PIO */
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if (host->board->bus_width_16)
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memcpy_toio(chip->IO_ADDR_W, buf, len);
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atmel_write_buf16(mtd, buf, len);
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else
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atmel_write_buf8(mtd, buf, len);
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}
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}
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/*
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/*
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