powerpc/t4240qds: fix PHY reset timeout issue

[karo-tx-uboot.git] / doc / README.nand

diff --git a/doc/README.nand b/doc/README.nand
index c130189587b81a21b1d51aa20cf11112b8eb89b3..a1a511c5339cbc8f9b6d71e1b13cf7e609fa9156 100644 (file)
--- a/doc/README.nand
+++ b/doc/README.nand
@@ -108,6 +108,9 @@ Configuration Options:
    CONFIG_CMD_NAND
       Enables NAND support and commmands.
 
    CONFIG_CMD_NAND
       Enables NAND support and commmands.
 

+   CONFIG_CMD_NAND_TORTURE
+      Enables the torture command (see description of this command below).
+

    CONFIG_MTD_NAND_ECC_JFFS2
       Define this if you want the Error Correction Code information in
       the out-of-band data to be formatted to match the JFFS2 file system.
    CONFIG_MTD_NAND_ECC_JFFS2
       Define this if you want the Error Correction Code information in
       the out-of-band data to be formatted to match the JFFS2 file system.


@@ -213,6 +216,24 @@ Miscellaneous and testing commands:
   DANGEROUS!!! Factory set bad blocks will be lost. Use only
   to remove artificial bad blocks created with the "markbad" command.
 
   DANGEROUS!!! Factory set bad blocks will be lost. Use only
   to remove artificial bad blocks created with the "markbad" command.
 

+  "torture offset"
+  Torture block to determine if it is still reliable.
+  Enabled by the CONFIG_CMD_NAND_TORTURE configuration option.
+  This command returns 0 if the block is still reliable, else 1.
+  If the block is detected as unreliable, it is up to the user to decide to
+  mark this block as bad.
+  The analyzed block is put through 3 erase / write cycles (or less if the block
+  is detected as unreliable earlier).
+  This command can be used in scripts, e.g. together with the markbad command to
+  automate retries and handling of possibly newly detected bad blocks if the
+  nand write command fails.
+  It can also be used manually by users having seen some NAND errors in logs to
+  search the root cause of these errors.
+  The underlying nand_torture() function is also useful for code willing to
+  automate actions following a nand->write() error. This would e.g. be required
+  in order to program or update safely firmware to NAND, especially for the UBI
+  part of such firmware.
+

 
 NAND locking command (for chips with active LOCKPRE pin)
 
 
 NAND locking command (for chips with active LOCKPRE pin)