RE: [PATCH v7 RESEND 07/13] spi: imx: fix ERR009165

[Robin Gong <yibin.gong@nxp.com>]

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On 2020/05/13 Sascha Hauer <s.hauer@pengutronix.de> wrote:
> On Wed, May 13, 2020 at 08:52:39AM +0000, Robin Gong wrote:
> > On 2020/05/13 16:48 Sascha Hauer <s.hauer@pengutronix.de> wrote:
> > > On Wed, May 13, 2020 at 08:38:26AM +0000, Robin Gong wrote:
> > > > On 2020/05/13 Sascha Hauer <s.hauer@pengutronix.de> wrote:
> > > > > This patch is the one bisecting will end up with when somebody
> > > > > uses an older SDMA firmware or the ROM scripts. It should have a
> > > > > better description what happens and what should be done about it.
> > > > Emm..That's true. Timeout will be caught in such case, hence,
> > > > maybe we can
> > > fall back it to pio always.
> > >
> > > With my patch applied sdma_load_context() will fail. I don't know
> > > how exactly this hits into the SPI driver, but it won't be a timeout.
> > Thanks for your quick test, assume you use ROM firmware, right?
> 
> Yes.
Would you please have a try with the attached patch which is based this patch set?

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From b4f9860be8cc8b9672626baa62a4cec89cf29e87 Mon Sep 17 00:00:00 2001
From: Robin Gong <yibin.gong@nxp.com>
Date: Thu, 14 May 2020 07:18:33 +0800
Subject: [PATCH v7 RESEND 14/14] spi: imx: fallback to PIO if dma setup
 failure

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 <yibin.gong@nxp.com>
---
 drivers/spi/spi-imx.c | 31 +++++++++++++++++++++++++++----
 1 file changed, 27 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index a57edcb..56505cb 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -72,6 +72,7 @@ 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;
@@ -496,6 +497,11 @@ 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;
@@ -1008,6 +1014,7 @@ 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,
@@ -1022,6 +1029,7 @@ 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,
@@ -1430,6 +1438,7 @@ 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;
 	}
 
@@ -1543,6 +1552,7 @@ 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))
@@ -1551,10 +1561,23 @@ 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_info(&spi->dev, "Fallback to PIO mode\n");
+	}
+
+	return spi_imx_pio_transfer(spi, transfer);
 }
 
 static int spi_imx_setup(struct spi_device *spi)
-- 
2.7.4