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path: root/drivers/spi/spi-xilinx.c
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Diffstat (limited to 'drivers/spi/spi-xilinx.c')
-rw-r--r--drivers/spi/spi-xilinx.c38
1 files changed, 24 insertions, 14 deletions
diff --git a/drivers/spi/spi-xilinx.c b/drivers/spi/spi-xilinx.c
index a339c1e99..300912117 100644
--- a/drivers/spi/spi-xilinx.c
+++ b/drivers/spi/spi-xilinx.c
@@ -270,6 +270,7 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
while (remaining_words) {
int n_words, tx_words, rx_words;
+ u32 sr;
n_words = min(remaining_words, xspi->buffer_size);
@@ -284,24 +285,33 @@ static int xilinx_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
if (use_irq) {
xspi->write_fn(cr, xspi->regs + XSPI_CR_OFFSET);
wait_for_completion(&xspi->done);
- } else
- while (!(xspi->read_fn(xspi->regs + XSPI_SR_OFFSET) &
- XSPI_SR_TX_EMPTY_MASK))
- ;
-
- /* A transmit has just completed. Process received data and
- * check for more data to transmit. Always inhibit the
- * transmitter while the Isr refills the transmit register/FIFO,
- * or make sure it is stopped if we're done.
- */
- if (use_irq)
+ /* A transmit has just completed. Process received data
+ * and check for more data to transmit. Always inhibit
+ * the transmitter while the Isr refills the transmit
+ * register/FIFO, or make sure it is stopped if we're
+ * done.
+ */
xspi->write_fn(cr | XSPI_CR_TRANS_INHIBIT,
- xspi->regs + XSPI_CR_OFFSET);
+ xspi->regs + XSPI_CR_OFFSET);
+ sr = XSPI_SR_TX_EMPTY_MASK;
+ } else
+ sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
/* Read out all the data from the Rx FIFO */
rx_words = n_words;
- while (rx_words--)
- xilinx_spi_rx(xspi);
+ while (rx_words) {
+ if ((sr & XSPI_SR_TX_EMPTY_MASK) && (rx_words > 1)) {
+ xilinx_spi_rx(xspi);
+ rx_words--;
+ continue;
+ }
+
+ sr = xspi->read_fn(xspi->regs + XSPI_SR_OFFSET);
+ if (!(sr & XSPI_SR_RX_EMPTY_MASK)) {
+ xilinx_spi_rx(xspi);
+ rx_words--;
+ }
+ }
remaining_words -= n_words;
}