[flashrom] [PATCH] Remove delays in JEDEC erase sequence

[Michael Karcher]

It is extremely unlikely that a chip not requiring delays in probe does
require them in erase. We observed unreliable erasing with a SST49LF004A
with these delays, so remove them if the are not required.

Signed-off-by: Michael Karcher <flashrom at mkarcher.dialup.fu-berlin.de>
---
 jedec.c |   33 +++++++++++++++++++++------------
 1 files changed, 21 insertions(+), 12 deletions(-)

diff --git a/jedec.c b/jedec.c
index 199c64d..822de88 100644
--- a/jedec.c
+++ b/jedec.c
@@ -242,21 +242,24 @@ static int erase_sector_jedec_common(struct flashchip *flash, unsigned int page,
 			      unsigned int pagesize, unsigned int mask)
 {
 	chipaddr bios = flash->virtual_memory;
+	int delay_us = 10;
+	if(flash->probe_timing != TIMING_ZERO)
+	        delay_us = 0;
 
 	/*  Issue the Sector Erase command   */
 	chip_writeb(0xAA, bios + (0x5555 & mask));
-	programmer_delay(10);
+	programmer_delay(delay_us);
 	chip_writeb(0x55, bios + (0x2AAA & mask));
-	programmer_delay(10);
+	programmer_delay(delay_us);
 	chip_writeb(0x80, bios + (0x5555 & mask));
-	programmer_delay(10);
+	programmer_delay(delay_us);
 
 	chip_writeb(0xAA, bios + (0x5555 & mask));
-	programmer_delay(10);
+	programmer_delay(delay_us);
 	chip_writeb(0x55, bios + (0x2AAA & mask));
-	programmer_delay(10);
+	programmer_delay(delay_us);
 	chip_writeb(0x30, bios + page);
-	programmer_delay(10);
+	programmer_delay(delay_us);
 
 	/* wait for Toggle bit ready         */
 	toggle_ready_jedec_slow(bios);
@@ -272,6 +275,9 @@ static int erase_block_jedec_common(struct flashchip *flash, unsigned int block,
 			     unsigned int blocksize, unsigned int mask)
 {
 	chipaddr bios = flash->virtual_memory;
+	int delay_us = 10;
+	if(flash->probe_timing != TIMING_ZERO)
+	        delay_us = 0;
 
 	/*  Issue the Sector Erase command   */
 	chip_writeb(0xAA, bios + (0x5555 & mask));
@@ -302,21 +308,24 @@ static int erase_chip_jedec_common(struct flashchip *flash, unsigned int mask)
 {
 	int total_size = flash->total_size * 1024;
 	chipaddr bios = flash->virtual_memory;
+	int delay_us = 10;
+	if(flash->probe_timing != TIMING_ZERO)
+	        delay_us = 0;
 
 	/*  Issue the JEDEC Chip Erase command   */
 	chip_writeb(0xAA, bios + (0x5555 & mask));
-	programmer_delay(10);
+	programmer_delay(delay_us);
 	chip_writeb(0x55, bios + (0x2AAA & mask));
-	programmer_delay(10);
+	programmer_delay(delay_us);
 	chip_writeb(0x80, bios + (0x5555 & mask));
-	programmer_delay(10);
+	programmer_delay(delay_us);
 
 	chip_writeb(0xAA, bios + (0x5555 & mask));
-	programmer_delay(10);
+	programmer_delay(delay_us);
 	chip_writeb(0x55, bios + (0x2AAA & mask));
-	programmer_delay(10);
+	programmer_delay(delay_us);
 	chip_writeb(0x10, bios + (0x5555 & mask));
-	programmer_delay(10);
+	programmer_delay(delay_us);
 
 	toggle_ready_jedec_slow(bios);
 
-- 
1.7.2.3