ARM: OMAP: omap_uwire: wait for tx complete before starting the next one

The TDR register shouldn't be written when the CSRB flag is set. The fix
solves the problem where one SPI transfer includes multiple 8 or 16 bit
tx elements and the current transfer can be corrupted by accessing the
TDR too early.

Signed-off-by: Imre Deak <imre.deak@nokia.com>
Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>

diff --git a/drivers/spi/omap_uwire.c b/drivers/spi/omap_uwire.c
index 3aa3890..cc26c0d 100644 (file)
--- a/drivers/spi/omap_uwire.c
+++ b/drivers/spi/omap_uwire.c
@@ -240,12 +240,13 @@ static int uwire_txrx(struct spi_device *spi, struct spi_transfer *t)
                        pr_debug("%s: write-%d =%04x\n",
                                        spi->dev.bus_id, bits, val);
 #endif
+                       if (wait_uwire_csr_flag(CSRB, 0, 0))
+                               goto eio;
+
                        uwire_write_reg(UWIRE_TDR, val);
 
                        /* start write */
                        val = START | w | (bits << 5);
-                       if (wait_uwire_csr_flag(CSRB, 0, 0))
-                               goto eio;
 
                        uwire_write_reg(UWIRE_CSR, val);
                        len -= bytes;