[v9,05/14] spi: imx: fallback to PIO if dma setup failure

Commit Message

Robin Gong June 5, 2020, 9:32 p.m. UTC

Fallback to PIO in case dma setup failed. For example, sdma firmware not
updated but ERR009165 workaroud added in kernel.

Signed-off-by: Robin Gong <[e-mail]>
Acked-by: Sascha Hauer <[e-mail]>
---
 drivers/spi/spi-imx.c | 31 +++++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

Comments

Mark Brown June 5, 2020, 3:01 p.m. UTC | #1

On Sat, Jun 06, 2020 at 05:32:26AM +0800, Robin Gong wrote:
> Fallback to PIO in case dma setup failed. For example, sdma firmware not
> updated but ERR009165 workaroud added in kernel.

Please do not submit new versions of already applied patches, please
submit incremental updates to the existing code.  Modifying existing
commits creates problems for other users building on top of those
commits so it's best practice to only change pubished git commits if
absolutely essential.

Patch

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index f4f28a4..b7a85e3 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -71,6 +71,7 @@  struct spi_imx_devtype_data {
 	void (*reset)(struct spi_imx_data *);
 	void (*setup_wml)(struct spi_imx_data *);
 	void (*disable)(struct spi_imx_data *);
+	void (*disable_dma)(struct spi_imx_data *);
 	bool has_dmamode;
 	bool has_slavemode;
 	unsigned int fifo_size;
@@ -485,6 +486,11 @@  static void mx51_ecspi_trigger(struct spi_imx_data *spi_imx)
 	writel(reg, spi_imx->base + MX51_ECSPI_CTRL);
 }
 
+static void mx51_disable_dma(struct spi_imx_data *spi_imx)
+{
+	writel(0, spi_imx->base + MX51_ECSPI_DMA);
+}
+
 static void mx51_ecspi_disable(struct spi_imx_data *spi_imx)
 {
 	u32 ctrl;
@@ -987,6 +993,7 @@  static struct spi_imx_devtype_data imx51_ecspi_devtype_data = {
 	.rx_available = mx51_ecspi_rx_available,
 	.reset = mx51_ecspi_reset,
 	.setup_wml = mx51_setup_wml,
+	.disable_dma = mx51_disable_dma,
 	.fifo_size = 64,
 	.has_dmamode = true,
 	.dynamic_burst = true,
@@ -1001,6 +1008,7 @@  static struct spi_imx_devtype_data imx53_ecspi_devtype_data = {
 	.prepare_transfer = mx51_ecspi_prepare_transfer,
 	.trigger = mx51_ecspi_trigger,
 	.rx_available = mx51_ecspi_rx_available,
+	.disable_dma = mx51_disable_dma,
 	.reset = mx51_ecspi_reset,
 	.fifo_size = 64,
 	.has_dmamode = true,
@@ -1385,6 +1393,7 @@  static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
 				DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
 	if (!desc_tx) {
 		dmaengine_terminate_all(master->dma_tx);
+		dmaengine_terminate_all(master->dma_rx);
 		return -EINVAL;
 	}
 
@@ -1498,6 +1507,7 @@  static int spi_imx_transfer(struct spi_device *spi,
 				struct spi_transfer *transfer)
 {
 	struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
+	int ret;
 
 	/* flush rxfifo before transfer */
 	while (spi_imx->devtype_data->rx_available(spi_imx))
@@ -1506,10 +1516,23 @@  static int spi_imx_transfer(struct spi_device *spi,
 	if (spi_imx->slave_mode)
 		return spi_imx_pio_transfer_slave(spi, transfer);
 
-	if (spi_imx->usedma)
-		return spi_imx_dma_transfer(spi_imx, transfer);
-	else
-		return spi_imx_pio_transfer(spi, transfer);
+	/*
+	 * fallback PIO mode if dma setup error happen, for example sdma
+	 * firmware may not be updated as ERR009165 required.
+	 */
+	if (spi_imx->usedma) {
+		ret = spi_imx_dma_transfer(spi_imx, transfer);
+		if (ret != -EINVAL)
+			return ret;
+
+		spi_imx->devtype_data->disable_dma(spi_imx);
+
+		spi_imx->usedma = false;
+		spi_imx->dynamic_burst = spi_imx->devtype_data->dynamic_burst;
+		dev_dbg(&spi->dev, "Fallback to PIO mode\n");
+	}
+
+	return spi_imx_pio_transfer(spi, transfer);
 }
 
 static int spi_imx_setup(struct spi_device *spi)