Handle delays/excessive latency during flash command processing with PIO.

Signed-off-by: Felix Fietkau <nbd@nbd.name>

--- a/drivers/mtd/nand/pxa3xx_nand.c
+++ b/drivers/mtd/nand/pxa3xx_nand.c
@@ -227,6 +227,7 @@ struct pxa3xx_nand_info {
 	int			use_dma;	/* use DMA ? */
 	int			use_spare;	/* use spare ? */
 	int			need_wait;
+	int			pio_progress;
 
 	/* Amount of real data per full chunk */
 	unsigned int		chunk_size;
@@ -769,6 +770,7 @@ static irqreturn_t pxa3xx_nand_irq_threa
 {
 	struct pxa3xx_nand_info *info = data;
 
+	info->pio_progress = 1;
 	handle_data_pio(info);
 
 	info->state = STATE_CMD_DONE;
@@ -1175,8 +1177,13 @@ static void nand_cmdfunc(struct mtd_info
 		info->need_wait = 1;
 		pxa3xx_nand_start(info);
 
+retry:
+		info->pio_progress = 0;
 		if (!wait_for_completion_timeout(&info->cmd_complete,
 		    CHIP_DELAY_TIMEOUT)) {
+			if (info->pio_progress)
+			    goto retry;
+
 			dev_err(&info->pdev->dev, "Wait time out!!!\n");
 			/* Stop State Machine for next command cycle */
 			pxa3xx_nand_stop(info);