[U-Boot] cfi: Problem with Intel Strata 28F320 flash

[Heiko Schocher]

Hello Philippe,

Philippe De Muyter wrote:
> On Tue, Mar 08, 2011 at 02:08:26PM +0100, Heiko Schocher wrote:
>> Hello,
>>
>> as I am actual trying to get the keymile boards in sync with actual
>> mainline u-boot, I faced the following Problem with an Intel Strata
>> Flash on the mgcoge (mpc8247 based board):
>>
>> I couldn;t unprotect/erase/write/protect some (not all!) Flash sectors.
>>
>> For Example, I could do this without errors on the sectors where
>> u-boot sits (First three sectors), but not with the environment (next
>> two sectors)!
> 
> That's exactly the problem I had, but triggered by another valid command
> sequence.
> 
> So it is also a flash bug.

Hmm.. I wouldn;t call it bug, because the sequence which is
run without 54652991caedc39b2ec2e5b49e750669bfcd1e2e, is exactly
the sequence, which is described in the datasheet for the 29Fxxx
chips ...

> Have you searched with google for your chip plus "errata" or "specification
> update" as they call that ?

No, see above comment.

>> After some debugging, I found out, that, if I revert commit
>>
>> commit 54652991caedc39b2ec2e5b49e750669bfcd1e2e
>> Author: Philippe De Muyter <phdm at macqel.be>
>> Date:   Tue Aug 17 18:40:25 2010 +0200
>>
>>     Work around bug in Numonyx P33/P30 256-Mbit 65nm flash chips.
>>
>>     I have "ported" U-boot to a in house made board with Numonyx Axcell P33/P30
>>     256-Mbit 65nm flash chips.
>>
>>     After some time :( searching for bugs in our board or soft, we have
>>     discovered that those chips have a small but annoying bug, documented in
>>     "Numonyx Axcell P33/P30 256-Mbit Specification Update"
>> [...]
>>
>> It works again fine, and without problems ... did somebody faced
>> similiar issues with the cfi driver? Some Ideas?
> 
> It seems like we'll need to check the flash chip type before issuing one command
> sequence or another.

Maybe a way to go ... more comments?

Below a patch, which introduces a function, which checks for
"protection bugfixes", and if no bugfix is found the old code is
executed. Just a fast RFC patch.

bye,
Heiko

diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
index dd394a8..9d3fdcc 100644
--- a/drivers/mtd/cfi_flash.c
+++ b/drivers/mtd/cfi_flash.c
@@ -1376,6 +1376,38 @@ int write_buff (flash_info_t * info, uchar * src, ulong addr, ulong cnt)
  */
 #ifdef CONFIG_SYS_FLASH_PROTECTION

+static int cfi_protect_bugfix(flash_info_t * info, long sector, int prot)
+{
+	if ((info->manufacturer_id == 0x89) && (info->device_id == 0x8922)) {
+		/*
+		 * see errata called
+		 * "Numonyx Axcell P33/P30 Specification Update" :)
+		 */
+		flash_write_cmd (info, sector, 0, FLASH_CMD_READ_ID);
+		if (!flash_isequal (info, sector, FLASH_OFFSET_PROTECT,
+				    prot)) {
+			/*
+			 * cmd must come before FLASH_CMD_PROTECT + 20us
+			 * Disable interrupts which might cause a timeout here.
+			 */
+			int flag = disable_interrupts ();
+			unsigned short cmd;
+				if (prot)
+				cmd = FLASH_CMD_PROTECT_SET;
+			else
+				cmd = FLASH_CMD_PROTECT_CLEAR;
+				flash_write_cmd (info, sector, 0,
+					  FLASH_CMD_PROTECT);
+			flash_write_cmd (info, sector, 0, cmd);
+			/* re-enable interrupts if necessary */
+			if (flag)
+				enable_interrupts ();
+		}
+		return 1;
+	}
+	return 0;
+}
+
 int flash_real_protect (flash_info_t * info, long sector, int prot)
 {
 	int retcode = 0;
@@ -1384,31 +1416,18 @@ int flash_real_protect (flash_info_t * info, long sector, int prot)
 		case CFI_CMDSET_INTEL_PROG_REGIONS:
 		case CFI_CMDSET_INTEL_STANDARD:
 		case CFI_CMDSET_INTEL_EXTENDED:
-			/*
-			 * see errata called
-			 * "Numonyx Axcell P33/P30 Specification Update" :)
-			 */
-			flash_write_cmd (info, sector, 0, FLASH_CMD_READ_ID);
-			if (!flash_isequal (info, sector, FLASH_OFFSET_PROTECT,
-					    prot)) {
-				/*
-				 * cmd must come before FLASH_CMD_PROTECT + 20us
-				 * Disable interrupts which might cause a timeout here.
-				 */
-				int flag = disable_interrupts ();
-				unsigned short cmd;
-
+			if (!cfi_protect_bugfix(info, sector, prot)) {
+				flash_write_cmd (info, sector, 0,
+					 FLASH_CMD_CLEAR_STATUS);
+				flash_write_cmd (info, sector, 0,
+					FLASH_CMD_PROTECT);
 				if (prot)
-					cmd = FLASH_CMD_PROTECT_SET;
+					flash_write_cmd (info, sector, 0,
+						FLASH_CMD_PROTECT_SET);
 				else
-					cmd = FLASH_CMD_PROTECT_CLEAR;
+					flash_write_cmd (info, sector, 0,
+						FLASH_CMD_PROTECT_CLEAR);

-				flash_write_cmd (info, sector, 0,
-						  FLASH_CMD_PROTECT);
-				flash_write_cmd (info, sector, 0, cmd);
-				/* re-enable interrupts if necessary */
-				if (flag)
-					enable_interrupts ();
 			}
 			break;
 		case CFI_CMDSET_AMD_EXTENDED:

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