From d9596ffbdc79cea285010b67dd20a4618303f624 Mon Sep 17 00:00:00 2001 From: Mike Frysinger Date: Thu, 2 Apr 2009 12:51:28 -0400 Subject: [PATCH] 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 CC: Jason McMullan CC: TsiChung Liew --- drivers/mtd/spi/stmicro.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/mtd/spi/stmicro.c b/drivers/mtd/spi/stmicro.c index b43e9f453a..9b910c13fd 100644 --- 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; } -- 2.39.5