mtd: mxc-nand: kill the NAND_MAX_PAGESIZE/NAND_MAX_OOBSIZE

We kill the NAND_MAX_PAGESIZE/NAND_MAX_OOBSIZE by the following way:
 1.) Before we call the nand_scan_ident, we allocate a temporary buffer
     whose size is PAGE_SIZE.
 2.) After we finish the nand_scan_ident, we have already getten the
     page size and oob size. We will allocate the right buffer size
     again.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Brian Norris <computersforpeace@gmail.com>

1 files changed, 15 insertions, 3 deletions

diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index 567a5e56660c..e9a4835c4dd9 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -1399,12 +1399,15 @@ static int mxcnd_probe(struct platform_device *pdev)
         int err = 0;
 
         /* Allocate memory for MTD device structure and private data */
-        host = devm_kzalloc(&pdev->dev, sizeof(struct mxc_nand_host) +
-                        NAND_MAX_PAGESIZE + NAND_MAX_OOBSIZE, GFP_KERNEL);
+        host = devm_kzalloc(&pdev->dev, sizeof(struct mxc_nand_host),
+                        GFP_KERNEL);
         if (!host)
                 return -ENOMEM;
 
-        host->data_buf = (uint8_t *)(host + 1);
+        /* allocate a temporary buffer for the nand_scan_ident() */
+        host->data_buf = devm_kzalloc(&pdev->dev, PAGE_SIZE, GFP_KERNEL);
+        if (!host->data_buf)
+                return -ENOMEM;
 
         host->dev = &pdev->dev;
         /* structures must be linked */
@@ -1532,6 +1535,15 @@ static int mxcnd_probe(struct platform_device *pdev)
                 goto escan;
         }
 
+        /* allocate the right size buffer now */
+        devm_kfree(&pdev->dev, (void *)host->data_buf);
+        host->data_buf = devm_kzalloc(&pdev->dev, mtd->writesize + mtd->oobsize,
+                                        GFP_KERNEL);
+        if (!host->data_buf) {
+                err = -ENOMEM;
+                goto escan;
+        }
+
         /* Call preset again, with correct writesize this time */
         host->devtype_data->preset(mtd);