mtd: pxa3xx_nand: enhance suspend and resume routine

This patch add protection on the suspend&resume path to prevent
some unexpected behavior, like interrupt occur at the very second
of resume back and it don't follow normal command path, which lead
to bug.

Signed-off-by: Lei Wen <leiwen@marvell.com>

1 files changed, 14 insertions, 1 deletions

diff --git a/drivers/mtd/nand/pxa3xx_nand.c b/drivers/mtd/nand/pxa3xx_nand.c
index b7db1b2021f..61e1ff5a9ad 100644
--- a/drivers/mtd/nand/pxa3xx_nand.c
+++ b/drivers/mtd/nand/pxa3xx_nand.c
@@ -1158,23 +1158,36 @@ static int pxa3xx_nand_probe(struct platform_device *pdev)
 static int pxa3xx_nand_suspend(struct platform_device *pdev, pm_message_t state)
 {
         struct pxa3xx_nand_info *info = platform_get_drvdata(pdev);
+        struct mtd_info *mtd = info->mtd;
 
         if (info->state) {
                 dev_err(&pdev->dev, "driver busy, state = %d\n", info->state);
                 return -EAGAIN;
         }
 
+        mtd->suspend(mtd);
         return 0;
 }
 
 static int pxa3xx_nand_resume(struct platform_device *pdev)
 {
         struct pxa3xx_nand_info *info = platform_get_drvdata(pdev);
+        struct mtd_info *mtd = info->mtd;
+
+        /* We don't want to handle interrupt without calling mtd routine */
+        disable_int(info, NDCR_INT_MASK);
 
         nand_writel(info, NDTR0CS0, info->ndtr0cs0);
         nand_writel(info, NDTR1CS0, info->ndtr1cs0);
-        clk_enable(info->clk);
 
+        /*
+         * As the spec says, the NDSR would be updated to 0x1800 when
+         * doing the nand_clk disable/enable.
+         * To prevent it damaging state machine of the driver, clear
+         * all status before resume
+         */
+        nand_writel(info, NDSR, NDSR_MASK);
+        mtd->resume(mtd);
         return 0;
 }
 #else