spi-nor: intel-spi: Fix broken software sequencing codes

There are two bugs in current intel_spi_sw_cycle():

- The 'data byte count' field should be the number of bytes
  transferred minus 1
- SSFSTS_CTL is the offset from ispi->sregs, not ispi->base

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Cc: <stable@vger.kernel.org> # v4.11+
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Cyrille Pitchen <cyrille.pitchen@wedev4u.fr>

diff --git a/drivers/mtd/spi-nor/intel-spi.c b/drivers/mtd/spi-nor/intel-spi.c
index 07626caa7b324576dd68af9e7489ea22521ab7c8..263c6ab5849a8942c50e592ae788928ec2338d9f 100644 (file)
--- a/drivers/mtd/spi-nor/intel-spi.c
+++ b/drivers/mtd/spi-nor/intel-spi.c
@@ -426,7 +426,7 @@ static int intel_spi_sw_cycle(struct intel_spi *ispi, u8 opcode, int len)
        if (ret < 0)
                return ret;
 
-       val = (len << SSFSTS_CTL_DBC_SHIFT) | SSFSTS_CTL_DS;
+       val = ((len - 1) << SSFSTS_CTL_DBC_SHIFT) | SSFSTS_CTL_DS;
        val |= ret << SSFSTS_CTL_COP_SHIFT;
        val |= SSFSTS_CTL_FCERR | SSFSTS_CTL_FDONE;
        val |= SSFSTS_CTL_SCGO;
@@ -436,7 +436,7 @@ static int intel_spi_sw_cycle(struct intel_spi *ispi, u8 opcode, int len)
        if (ret)
                return ret;
 
-       status = readl(ispi->base + SSFSTS_CTL);
+       status = readl(ispi->sregs + SSFSTS_CTL);
        if (status & SSFSTS_CTL_FCERR)
                return -EIO;
        else if (status & SSFSTS_CTL_AEL)