3.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> commit 8dad0386b97c4bd6edd56752ca7f2e735fe5beb4 upstream. The NDDB register holds the data that are needed by the read and write commands. However, during a read PIO access, the datasheet specifies that after each 32 bytes read in that register, when BCH is enabled, we have to make sure that the RDDREQ bit is set in the NDSR register. This fixes an issue that was seen on the Armada 385, and presumably other mvebu SoCs, when a read on a newly erased page would end up in the driver reporting a timeout from the NAND. Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> Reviewed-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx> Acked-by: Ezequiel Garcia <ezequiel.garcia@xxxxxxxxxxxxxxxxxx> Signed-off-by: Brian Norris <computersforpeace@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/mtd/nand/pxa3xx_nand.c | 48 +++++++++++++++++++++++++++++++++++------ 1 file changed, 42 insertions(+), 6 deletions(-) --- a/drivers/mtd/nand/pxa3xx_nand.c +++ b/drivers/mtd/nand/pxa3xx_nand.c @@ -480,6 +480,42 @@ static void disable_int(struct pxa3xx_na nand_writel(info, NDCR, ndcr | int_mask); } +static void drain_fifo(struct pxa3xx_nand_info *info, void *data, int len) +{ + if (info->ecc_bch) { + int timeout; + + /* + * According to the datasheet, when reading from NDDB + * with BCH enabled, after each 32 bytes reads, we + * have to make sure that the NDSR.RDDREQ bit is set. + * + * Drain the FIFO 8 32 bits reads at a time, and skip + * the polling on the last read. + */ + while (len > 8) { + __raw_readsl(info->mmio_base + NDDB, data, 8); + + for (timeout = 0; + !(nand_readl(info, NDSR) & NDSR_RDDREQ); + timeout++) { + if (timeout >= 5) { + dev_err(&info->pdev->dev, + "Timeout on RDDREQ while draining the FIFO\n"); + return; + } + + mdelay(1); + } + + data += 32; + len -= 8; + } + } + + __raw_readsl(info->mmio_base + NDDB, data, len); +} + static void handle_data_pio(struct pxa3xx_nand_info *info) { unsigned int do_bytes = min(info->data_size, info->chunk_size); @@ -496,14 +532,14 @@ static void handle_data_pio(struct pxa3x DIV_ROUND_UP(info->oob_size, 4)); break; case STATE_PIO_READING: - __raw_readsl(info->mmio_base + NDDB, - info->data_buff + info->data_buff_pos, - DIV_ROUND_UP(do_bytes, 4)); + drain_fifo(info, + info->data_buff + info->data_buff_pos, + DIV_ROUND_UP(do_bytes, 4)); if (info->oob_size > 0) - __raw_readsl(info->mmio_base + NDDB, - info->oob_buff + info->oob_buff_pos, - DIV_ROUND_UP(info->oob_size, 4)); + drain_fifo(info, + info->oob_buff + info->oob_buff_pos, + DIV_ROUND_UP(info->oob_size, 4)); break; default: dev_err(&info->pdev->dev, "%s: invalid state %d\n", __func__, -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html