spi: dw: Wait for idle after TX

If this is a DMA transfer, and if there is no simultaneous RX transfer, wait for the interface to go idle before reporting that TX is done. Link: https://forums.raspberrypi.com/viewtopic.php?t=383027 Signed-off-by: Phil Elwell <[email protected]>
raspberrypi · Feb 4, 2025 · 54a442d · 54a442d
1 parent 8a08b4a
commit 54a442d
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/drivers/spi/spi-dw-dma.c b/drivers/spi/spi-dw-dma.c
@@ -304,6 +304,11 @@ static int dw_spi_dma_wait_tx_done(struct dw_spi *dws,
 		return -EIO;
 	}
 
+	if (!xfer->rx_buf) {
+		while (dw_readl(dws, DW_SPI_SR) & DW_SPI_SR_BUSY)
+			cpu_relax();
+	}
+
 	return 0;
 }