sf: stmicro: dont send 4 bytes when reading status register
I can't find anywhere in the datasheet that says the status register needs
3 dummy bytes sent to it before being able to read back the first real
result. Tests on a Blackfin board show that after writing the opcode, the
status register starts coming back immediately. So only write out the
read status register opcode before polling the result.
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
CC: Jason McMullan <mcmullan@netapp.com>
CC: TsiChung Liew <Tsi-Chung.Liew@freescale.com>
diff --git a/drivers/mtd/spi/stmicro.c b/drivers/mtd/spi/stmicro.c
index b43e9f4..9b910c1 100644
--- a/drivers/mtd/spi/stmicro.c
+++ b/drivers/mtd/spi/stmicro.c
@@ -133,12 +133,12 @@
struct spi_slave *spi = flash->spi;
unsigned long timebase;
int ret;
+ u8 cmd = CMD_M25PXX_RDSR;
u8 status;
- u8 cmd[4] = { CMD_M25PXX_RDSR, 0xff, 0xff, 0xff };
- ret = spi_xfer(spi, 32, &cmd[0], NULL, SPI_XFER_BEGIN);
+ ret = spi_xfer(spi, 8, &cmd, NULL, SPI_XFER_BEGIN);
if (ret) {
- debug("SF: Failed to send command %02x: %d\n", cmd[0], ret);
+ debug("SF: Failed to send command %02x: %d\n", cmd, ret);
return ret;
}