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 b43e9f453ac602bb3c26732152ba976d81a91df7..9b910c13fd8b16f13fb92543d07f2e8e859d684e 100644 (file)
--- a/drivers/mtd/spi/stmicro.c
+++ b/drivers/mtd/spi/stmicro.c
@@ -133,12 +133,12 @@ static int stmicro_wait_ready(struct spi_flash *flash, unsigned long timeout)
        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;
        }