cfi_flash: Fix problems with status/id read mode

This patch adds some calls to set the flash chip in the read-status-
register- or read-id-mode before the corresponding register is
read back. This problem was detected while porting the common CFI
driver to support the Xilinx DS617 flash chips.

Signed-off-by: Stefan Roese <sr@denx.de>

diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
index 39c235ebc2641978efa45bc69b28c0d2af63e3c8..643cd877314e96837ad5e7c86c43b9b9688ee890 100644 (file)
--- a/drivers/mtd/cfi_flash.c
+++ b/drivers/mtd/cfi_flash.c
@@ -1426,6 +1426,11 @@ int flash_real_protect (flash_info_t * info, long sector, int prot)
 #endif
        };
 
+       /*
+        * Flash needs to be in status register read mode for
+        * flash_full_status_check() to work correctly
+        */
+       flash_write_cmd(info, sector, 0, FLASH_CMD_READ_STATUS);
        if ((retcode =
             flash_full_status_check (info, sector, info->erase_blk_tout,
                                      prot ? "protect" : "unprotect")) == 0) {
@@ -1975,6 +1980,13 @@ ulong flash_get_size (phys_addr_t base, int banknum)
                                case CFI_CMDSET_INTEL_PROG_REGIONS:
                                case CFI_CMDSET_INTEL_EXTENDED:
                                case CFI_CMDSET_INTEL_STANDARD:
+                                       /*
+                                        * Set flash to read-id mode. Otherwise
+                                        * reading protected status is not
+                                        * guaranteed.
+                                        */
+                                       flash_write_cmd(info, sect_cnt, 0,
+                                                       FLASH_CMD_READ_ID);
                                        info->protect[sect_cnt] =
                                                flash_isset (info, sect_cnt,
                                                             FLASH_OFFSET_PROTECT,