Merge tag 'spi-v4.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi

Pull spi fixes from Mark Brown:
 "A collection of driver specific fixes to which the usual comments
  about them being important if you see them mostly apply (except for
  the comment fix).  The pl022 one is particularly nasty for anyone
  affected by it"

* tag 'spi-v4.0-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
  spi: pl022: Fix race in giveback() leading to driver lock-up
  spi: dw-mid: avoid potential NULL dereference
  spi: img-spfi: Verify max spfi transfer length
  spi: fix a typo in comment.
  spi: atmel: Fix interrupt setup for PDC transfers
  spi: dw: revisit FIFO size detection again
  spi: dw-pci: correct number of chip selects
  drivers: spi: ti-qspi: wait for busy bit clear before data write/read

1 files changed, 22 insertions, 0 deletions

diff --git a/drivers/spi/spi-ti-qspi.c b/drivers/spi/spi-ti-qspi.c
index 884a716e50cb..5c0616870358 100644
--- a/drivers/spi/spi-ti-qspi.c
+++ b/drivers/spi/spi-ti-qspi.c
@@ -101,6 +101,7 @@ struct ti_qspi {
 #define QSPI_FLEN(n)			((n - 1) << 0)
 
 /* STATUS REGISTER */
+#define BUSY				0x01
 #define WC				0x02
 
 /* INTERRUPT REGISTER */
@@ -199,6 +200,21 @@ static void ti_qspi_restore_ctx(struct ti_qspi *qspi)
 	ti_qspi_write(qspi, ctx_reg->clkctrl, QSPI_SPI_CLOCK_CNTRL_REG);
 }
 
+static inline u32 qspi_is_busy(struct ti_qspi *qspi)
+{
+	u32 stat;
+	unsigned long timeout = jiffies + QSPI_COMPLETION_TIMEOUT;
+
+	stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
+	while ((stat & BUSY) && time_after(timeout, jiffies)) {
+		cpu_relax();
+		stat = ti_qspi_read(qspi, QSPI_SPI_STATUS_REG);
+	}
+
+	WARN(stat & BUSY, "qspi busy\n");
+	return stat & BUSY;
+}
+
 static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t)
 {
 	int wlen, count;
@@ -211,6 +227,9 @@ static int qspi_write_msg(struct ti_qspi *qspi, struct spi_transfer *t)
 	wlen = t->bits_per_word >> 3;	/* in bytes */
 
 	while (count) {
+		if (qspi_is_busy(qspi))
+			return -EBUSY;
+
 		switch (wlen) {
 		case 1:
 			dev_dbg(qspi->dev, "tx cmd %08x dc %08x data %02x\n",
@@ -266,6 +285,9 @@ static int qspi_read_msg(struct ti_qspi *qspi, struct spi_transfer *t)
 
 	while (count) {
 		dev_dbg(qspi->dev, "rx cmd %08x dc %08x\n", cmd, qspi->dc);
+		if (qspi_is_busy(qspi))
+			return -EBUSY;
+
 		ti_qspi_write(qspi, cmd, QSPI_SPI_CMD_REG);
 		if (!wait_for_completion_timeout(&qspi->transfer_complete,
 						 QSPI_COMPLETION_TIMEOUT)) {