[U-Boot-Users] CFI Driver Fencepost Bugfix

Jon Loeliger jdl at freescale.com
Mon Dec 6 21:19:41 CET 2004


If you apply York's patch to enhance the CFI driver,
you will need this bug fix as well.  Applying this patch
allows the use of a PROMjet ICE to replace a FLASH bank
but still appear to use the CFI driver.  In this case,
the CFI driver just fails to recognize it as a valid
CFI device and the bank is treated like normal RAM.

While this was the behaviour, after York's patch is applied,
there is a lingering fencepost error after coming out of
the CFI detection loop that leaves the info->portwidth
and info->chipwidth at an index beyond the array used
in York's patch for address calculation.  When the
subsequent flash_write_cmd() is executed, random results
were possible.

This patch prevents that fencepost error, and is must be
applied after York's CFI driver patch.  (Technically the
logical patch can be applied, but the line numbers are
post-York's patch.)


* Patch by Jon Loeliger, Kumar Gala, 2004-12-03
  - Fix a fencepost error with York's previous patch to the
    CFI driver for the case where the FLASH banks aren't
    actually CFI devices.  This prevents oversubscripting
    the offset_multiply[] array.

Index: drivers/cfi_flash.c
RCS file: /cm/vault/u-boot/u-boot/drivers/cfi_flash.c,v
retrieving revision
retrieving revision
diff -u -r1. -r1.
--- drivers/cfi_flash.c	22 Nov 2004 17:50:25 -0000
+++ drivers/cfi_flash.c	3 Dec 2004 18:03:31 -0000
@@ -1253,6 +1253,9 @@
 		if ((info->interface == FLASH_CFI_X8X16) && (info->chipwidth ==
 			info->portwidth >>= 1;	/* XXX - Need to test on x8/x16 in parallel.
+	} else {
+		info->portwidth = 1;
+		info->chipwidth = 1;
 	flash_write_cmd (info, 0, 0, FLASH_CMD_RESET);

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