[PATCH v3 0/9] Some fixes for spi-s3c64xx

[PATCH v3 0/9] Some fixes for spi-s3c64xx

[Łukasz Stelmach]

This is a series of fixes created during porting a device driver (these
patches will be released soon too) for an SPI device to the current kernel.

The two most important are

  spi: spi-s3c64xx: swap s3c64xx_spi_set_cs() and s3c64xx_enable_datapath()
  spi: spi-s3s64xx: Add S3C64XX_SPI_QUIRK_CS_AUTO for Exynos3250

Without them DMA transfers larger than 512 bytes from the SPI controller
would fail.

Łukasz Stelmach (9):
  spi: spi-s3c64xx: swap s3c64xx_spi_set_cs() and
    s3c64xx_enable_datapath()
  spi: spi-s3s64xx: Add S3C64XX_SPI_QUIRK_CS_AUTO for Exynos3250
  spi: spi-s3c64xx: Check return values
  spi: spi-s3c64xx: Report more information when errors occur
  spi: spi-s3c64xx: Rename S3C64XX_SPI_SLAVE_* to S3C64XX_SPI_CS_*
  spi: spi-s3c64xx: Fix doc comment for struct s3c64xx_spi_driver_data
  spi: spi-s3c64xx: Ensure cur_speed holds actual clock value
  spi: spi-s3c64xx: Increase transfer timeout
  spi: spi-s3c64xx: Turn on interrupts upon resume

 drivers/spi/spi-s3c64xx.c | 111 +++++++++++++++++++++++++++-----------
 1 file changed, 79 insertions(+), 32 deletions(-)

Changes in v3:
  - added Reviewed-by and Suggested-by tags to commit messages
  - added information about non-CMU case in the commit message
    of (Ensure cur_speed holds actual clock value)

Changes in v2:
  - added missing commit descriptions
  - added spi: spi-s3c64xx: Ensure cur_speed holds actual clock value
  - implemented error propagation in
      spi: spi-s3c64xx: Check return values
  - rebased onto v5.9-rc1 which contains
      spi: spi-s3c64xx: Add missing entries for structs 's3c64xx_spi_dma_data' and 's3c64xx_spi_dma_data'
-- 
2.26.2

[PATCH v3 1/9] spi: spi-s3c64xx: swap s3c64xx_spi_set_cs() and s3c64xx_enable_datapath()

[Łukasz Stelmach]

Fix issues with DMA transfers bigger than 512 bytes on Exynos3250. Without
the patches such transfers fail to complete. This solution to the problem
is found in the vendor kernel for ARTIK5 boards based on Exynos3250.

Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
---
 drivers/spi/spi-s3c64xx.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 924b24441789..26c7cb79cd78 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -685,11 +685,11 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master,
 		sdd->state &= ~RXBUSY;
 		sdd->state &= ~TXBUSY;
 
-		s3c64xx_enable_datapath(sdd, xfer, use_dma);
-
 		/* Start the signals */
 		s3c64xx_spi_set_cs(spi, true);
 
+		s3c64xx_enable_datapath(sdd, xfer, use_dma);
+
 		spin_unlock_irqrestore(&sdd->lock, flags);
 
 		if (use_dma)
-- 
2.26.2

[PATCH v3 2/9] spi: spi-s3s64xx: Add S3C64XX_SPI_QUIRK_CS_AUTO for Exynos3250

[Łukasz Stelmach]

Fix issues with DMA transfers bigger than 512 bytes on Exynos3250. Without
the patches such transfers fail.

The vendor kernel for ARTIK5 handles CS in a simmilar way.

Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 drivers/spi/spi-s3c64xx.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 26c7cb79cd78..4a9ca9a99857 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -1379,6 +1379,7 @@ static struct s3c64xx_spi_port_config exynos4_spi_port_config = {
 	.tx_st_done	= 25,
 	.high_speed	= true,
 	.clk_from_cmu	= true,
+	.quirks		= S3C64XX_SPI_QUIRK_CS_AUTO,
 };
 
 static struct s3c64xx_spi_port_config exynos7_spi_port_config = {
-- 
2.26.2

[PATCH v3 3/9] spi: spi-s3c64xx: Check return values

[Łukasz Stelmach]

Check return values in prepare_dma() and s3c64xx_spi_config() and
propagate errors upwards.

Fixes: 788437273fa8 ("spi: s3c64xx: move to generic dmaengine API")
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
---
 drivers/spi/spi-s3c64xx.c | 50 ++++++++++++++++++++++++++++++++-------
 1 file changed, 41 insertions(+), 9 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 4a9ca9a99857..48afd4818558 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -122,6 +122,7 @@
 
 struct s3c64xx_spi_dma_data {
 	struct dma_chan *ch;
+	dma_cookie_t cookie;
 	enum dma_transfer_direction direction;
 };
 
@@ -271,12 +272,13 @@ static void s3c64xx_spi_dmacb(void *data)
 	spin_unlock_irqrestore(&sdd->lock, flags);
 }
 
-static void prepare_dma(struct s3c64xx_spi_dma_data *dma,
+static int prepare_dma(struct s3c64xx_spi_dma_data *dma,
 			struct sg_table *sgt)
 {
 	struct s3c64xx_spi_driver_data *sdd;
 	struct dma_slave_config config;
 	struct dma_async_tx_descriptor *desc;
+	int ret;
 
 	memset(&config, 0, sizeof(config));
 
@@ -300,12 +302,24 @@ static void prepare_dma(struct s3c64xx_spi_dma_data *dma,
 
 	desc = dmaengine_prep_slave_sg(dma->ch, sgt->sgl, sgt->nents,
 				       dma->direction, DMA_PREP_INTERRUPT);
+	if (!desc) {
+		dev_err(&sdd->pdev->dev, "unable to prepare %s scatterlist",
+			dma->direction == DMA_DEV_TO_MEM ? "rx" : "tx");
+		return -ENOMEM;
+	}
 
 	desc->callback = s3c64xx_spi_dmacb;
 	desc->callback_param = dma;
 
-	dmaengine_submit(desc);
+	dma->cookie = dmaengine_submit(desc);
+	ret = dma_submit_error(dma->cookie);
+	if (ret) {
+		dev_err(&sdd->pdev->dev, "DMA submission failed");
+		return -EIO;
+	}
+
 	dma_async_issue_pending(dma->ch);
+	return 0;
 }
 
 static void s3c64xx_spi_set_cs(struct spi_device *spi, bool enable)
@@ -355,11 +369,12 @@ static bool s3c64xx_spi_can_dma(struct spi_master *master,
 	return xfer->len > (FIFO_LVL_MASK(sdd) >> 1) + 1;
 }
 
-static void s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
+static int s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
 				    struct spi_transfer *xfer, int dma_mode)
 {
 	void __iomem *regs = sdd->regs;
 	u32 modecfg, chcfg;
+	int ret = 0;
 
 	modecfg = readl(regs + S3C64XX_SPI_MODE_CFG);
 	modecfg &= ~(S3C64XX_SPI_MODE_TXDMA_ON | S3C64XX_SPI_MODE_RXDMA_ON);
@@ -385,7 +400,7 @@ static void s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
 		chcfg |= S3C64XX_SPI_CH_TXCH_ON;
 		if (dma_mode) {
 			modecfg |= S3C64XX_SPI_MODE_TXDMA_ON;
-			prepare_dma(&sdd->tx_dma, &xfer->tx_sg);
+			ret = prepare_dma(&sdd->tx_dma, &xfer->tx_sg);
 		} else {
 			switch (sdd->cur_bpw) {
 			case 32:
@@ -417,12 +432,17 @@ static void s3c64xx_enable_datapath(struct s3c64xx_spi_driver_data *sdd,
 			writel(((xfer->len * 8 / sdd->cur_bpw) & 0xffff)
 					| S3C64XX_SPI_PACKET_CNT_EN,
 					regs + S3C64XX_SPI_PACKET_CNT);
-			prepare_dma(&sdd->rx_dma, &xfer->rx_sg);
+			ret = prepare_dma(&sdd->rx_dma, &xfer->rx_sg);
 		}
 	}
 
+	if (ret)
+		return ret;
+
 	writel(modecfg, regs + S3C64XX_SPI_MODE_CFG);
 	writel(chcfg, regs + S3C64XX_SPI_CH_CFG);
+
+	return 0;
 }
 
 static u32 s3c64xx_spi_wait_for_timeout(struct s3c64xx_spi_driver_data *sdd,
@@ -555,9 +575,10 @@ static int s3c64xx_wait_for_pio(struct s3c64xx_spi_driver_data *sdd,
 	return 0;
 }
 
-static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
+static int s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
 {
 	void __iomem *regs = sdd->regs;
+	int ret;
 	u32 val;
 
 	/* Disable Clock */
@@ -605,7 +626,9 @@ static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
 
 	if (sdd->port_conf->clk_from_cmu) {
 		/* The src_clk clock is divided internally by 2 */
-		clk_set_rate(sdd->src_clk, sdd->cur_speed * 2);
+		ret = clk_set_rate(sdd->src_clk, sdd->cur_speed * 2);
+		if (ret)
+			return ret;
 	} else {
 		/* Configure Clock */
 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
@@ -619,6 +642,8 @@ static void s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
 		val |= S3C64XX_SPI_ENCLK_ENABLE;
 		writel(val, regs + S3C64XX_SPI_CLK_CFG);
 	}
+
+	return 0;
 }
 
 #define XFER_DMAADDR_INVALID DMA_BIT_MASK(32)
@@ -661,7 +686,9 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master,
 		sdd->cur_bpw = bpw;
 		sdd->cur_speed = speed;
 		sdd->cur_mode = spi->mode;
-		s3c64xx_spi_config(sdd);
+		status = s3c64xx_spi_config(sdd);
+		if (status)
+			return status;
 	}
 
 	if (!is_polling(sdd) && (xfer->len > fifo_len) &&
@@ -688,10 +715,15 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master,
 		/* Start the signals */
 		s3c64xx_spi_set_cs(spi, true);
 
-		s3c64xx_enable_datapath(sdd, xfer, use_dma);
+		status = s3c64xx_enable_datapath(sdd, xfer, use_dma);
 
 		spin_unlock_irqrestore(&sdd->lock, flags);
 
+		if (status) {
+			dev_err(&spi->dev, "failed to enable data path for transfer: %d\n", status);
+			break;
+		}
+
 		if (use_dma)
 			status = s3c64xx_wait_for_dma(sdd, xfer);
 		else
-- 
2.26.2

[PATCH v3 4/9] spi: spi-s3c64xx: Report more information when errors occur

[Łukasz Stelmach]

Report amount of pending data when a transfer stops due to errors.

Report if DMA was used to transfer data and print the status code.

Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
---
 drivers/spi/spi-s3c64xx.c | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 48afd4818558..86b6125b24a6 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -731,17 +731,28 @@ static int s3c64xx_spi_transfer_one(struct spi_master *master,
 
 		if (status) {
 			dev_err(&spi->dev,
-				"I/O Error: rx-%d tx-%d res:rx-%c tx-%c len-%d\n",
+				"I/O Error: rx-%d tx-%d rx-%c tx-%c len-%d dma-%d res-(%d)\n",
 				xfer->rx_buf ? 1 : 0, xfer->tx_buf ? 1 : 0,
 				(sdd->state & RXBUSY) ? 'f' : 'p',
 				(sdd->state & TXBUSY) ? 'f' : 'p',
-				xfer->len);
+				xfer->len, use_dma ? 1 : 0, status);
 
 			if (use_dma) {
-				if (xfer->tx_buf && (sdd->state & TXBUSY))
+				struct dma_tx_state s;
+
+				if (xfer->tx_buf && (sdd->state & TXBUSY)) {
+					dmaengine_pause(sdd->tx_dma.ch);
+					dmaengine_tx_status(sdd->tx_dma.ch, sdd->tx_dma.cookie, &s);
 					dmaengine_terminate_all(sdd->tx_dma.ch);
-				if (xfer->rx_buf && (sdd->state & RXBUSY))
+					dev_err(&spi->dev, "TX residue: %d\n", s.residue);
+
+				}
+				if (xfer->rx_buf && (sdd->state & RXBUSY)) {
+					dmaengine_pause(sdd->rx_dma.ch);
+					dmaengine_tx_status(sdd->rx_dma.ch, sdd->rx_dma.cookie, &s);
 					dmaengine_terminate_all(sdd->rx_dma.ch);
+					dev_err(&spi->dev, "RX residue: %d\n", s.residue);
+				}
 			}
 		} else {
 			s3c64xx_flush_fifo(sdd);
-- 
2.26.2

[PATCH v3 5/9] spi: spi-s3c64xx: Rename S3C64XX_SPI_SLAVE_* to S3C64XX_SPI_CS_*

[Łukasz Stelmach]

Rename S3C64XX_SPI_SLAVE_* to S3C64XX_SPI_CS_* to match documentation.

Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
---
 drivers/spi/spi-s3c64xx.c | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 86b6125b24a6..13b53f9a5c3e 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -29,7 +29,7 @@
 #define S3C64XX_SPI_CH_CFG		0x00
 #define S3C64XX_SPI_CLK_CFG		0x04
 #define S3C64XX_SPI_MODE_CFG		0x08
-#define S3C64XX_SPI_SLAVE_SEL		0x0C
+#define S3C64XX_SPI_CS_REG		0x0C
 #define S3C64XX_SPI_INT_EN		0x10
 #define S3C64XX_SPI_STATUS		0x14
 #define S3C64XX_SPI_TX_DATA		0x18
@@ -64,9 +64,9 @@
 #define S3C64XX_SPI_MODE_TXDMA_ON		(1<<1)
 #define S3C64XX_SPI_MODE_4BURST			(1<<0)
 
-#define S3C64XX_SPI_SLAVE_AUTO			(1<<1)
-#define S3C64XX_SPI_SLAVE_SIG_INACT		(1<<0)
-#define S3C64XX_SPI_SLAVE_NSC_CNT_2		(2<<4)
+#define S3C64XX_SPI_CS_NSC_CNT_2		(2<<4)
+#define S3C64XX_SPI_CS_AUTO			(1<<1)
+#define S3C64XX_SPI_CS_SIG_INACT		(1<<0)
 
 #define S3C64XX_SPI_INT_TRAILING_EN		(1<<6)
 #define S3C64XX_SPI_INT_RX_OVERRUN_EN		(1<<5)
@@ -332,18 +332,18 @@ static void s3c64xx_spi_set_cs(struct spi_device *spi, bool enable)
 
 	if (enable) {
 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO)) {
-			writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
+			writel(0, sdd->regs + S3C64XX_SPI_CS_REG);
 		} else {
-			u32 ssel = readl(sdd->regs + S3C64XX_SPI_SLAVE_SEL);
+			u32 ssel = readl(sdd->regs + S3C64XX_SPI_CS_REG);
 
-			ssel |= (S3C64XX_SPI_SLAVE_AUTO |
-						S3C64XX_SPI_SLAVE_NSC_CNT_2);
-			writel(ssel, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
+			ssel |= (S3C64XX_SPI_CS_AUTO |
+						S3C64XX_SPI_CS_NSC_CNT_2);
+			writel(ssel, sdd->regs + S3C64XX_SPI_CS_REG);
 		}
 	} else {
 		if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
-			writel(S3C64XX_SPI_SLAVE_SIG_INACT,
-			       sdd->regs + S3C64XX_SPI_SLAVE_SEL);
+			writel(S3C64XX_SPI_CS_SIG_INACT,
+			       sdd->regs + S3C64XX_SPI_CS_REG);
 	}
 }
 
@@ -982,9 +982,9 @@ static void s3c64xx_spi_hwinit(struct s3c64xx_spi_driver_data *sdd)
 	sdd->cur_speed = 0;
 
 	if (sci->no_cs)
-		writel(0, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
+		writel(0, sdd->regs + S3C64XX_SPI_CS_REG);
 	else if (!(sdd->port_conf->quirks & S3C64XX_SPI_QUIRK_CS_AUTO))
-		writel(S3C64XX_SPI_SLAVE_SIG_INACT, sdd->regs + S3C64XX_SPI_SLAVE_SEL);
+		writel(S3C64XX_SPI_CS_SIG_INACT, sdd->regs + S3C64XX_SPI_CS_REG);
 
 	/* Disable Interrupts - we use Polling if not DMA mode */
 	writel(0, regs + S3C64XX_SPI_INT_EN);
-- 
2.26.2

[PATCH v3 6/9] spi: spi-s3c64xx: Fix doc comment for struct s3c64xx_spi_driver_data

[Łukasz Stelmach]

Remove descriptions for non-existent fields and fix indentation.

Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
---
 drivers/spi/spi-s3c64xx.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 13b53f9a5c3e..f85f40fd608c 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -162,11 +162,8 @@ struct s3c64xx_spi_port_config {
  * @cntrlr_info: Platform specific data for the controller this driver manages.
  * @lock: Controller specific lock.
  * @state: Set of FLAGS to indicate status.
- * @rx_dmach: Controller's DMA channel for Rx.
- * @tx_dmach: Controller's DMA channel for Tx.
  * @sfr_start: BUS address of SPI controller regs.
  * @regs: Pointer to ioremap'ed controller registers.
- * @irq: interrupt
  * @xfer_completion: To indicate completion of xfer task.
  * @cur_mode: Stores the active configuration of the controller.
  * @cur_bpw: Stores the active bits per word settings.
@@ -183,7 +180,7 @@ struct s3c64xx_spi_driver_data {
 	struct clk                      *ioclk;
 	struct platform_device          *pdev;
 	struct spi_master               *master;
-	struct s3c64xx_spi_info  *cntrlr_info;
+	struct s3c64xx_spi_info         *cntrlr_info;
 	spinlock_t                      lock;
 	unsigned long                   sfr_start;
 	struct completion               xfer_completion;
-- 
2.26.2

[PATCH v3 7/9] spi: spi-s3c64xx: Ensure cur_speed holds actual clock value

[Łukasz Stelmach]

Make sure the cur_speed value used in s3c64xx_enable_datapath()
to configure DMA channel and in s3c64xx_wait_for_*() to calculate the
transfer timeout is set to the actual value of (half) the clock speed.

Don't change non-CMU case, because no frequency calculation errors have
been reported.

Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Suggested-by: Tomasz Figa <tomasz.figa@gmail.com>
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
---
 drivers/spi/spi-s3c64xx.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index f85f40fd608c..0bd3e230350c 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -626,6 +626,7 @@ static int s3c64xx_spi_config(struct s3c64xx_spi_driver_data *sdd)
 		ret = clk_set_rate(sdd->src_clk, sdd->cur_speed * 2);
 		if (ret)
 			return ret;
+		sdd->cur_speed = clk_get_rate(sdd->src_clk) / 2;
 	} else {
 		/* Configure Clock */
 		val = readl(regs + S3C64XX_SPI_CLK_CFG);
-- 
2.26.2

Re: [PATCH v3 7/9] spi: spi-s3c64xx: Ensure cur_speed holds actual clock value

[Krzysztof Kozlowski]

On Fri, Oct 02, 2020 at 02:22:41PM +0200, Łukasz Stelmach wrote:
> Make sure the cur_speed value used in s3c64xx_enable_datapath()
> to configure DMA channel and in s3c64xx_wait_for_*() to calculate the
> transfer timeout is set to the actual value of (half) the clock speed.
> 
> Don't change non-CMU case, because no frequency calculation errors have
> been reported.
> 
> Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
> Suggested-by: Tomasz Figa <tomasz.figa@gmail.com>
> Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>

For the future, tags are added in chronological order, so first is
suggested (as someone suggested to make a patch), then your SoB (as you
wrote it) and then my review (because you had to write a patch before I
could review).

All other patches here have these mixed up. No need to resend, but keep
it in mind for the future.

Best regards,
Krzysztof

[PATCH v3 8/9] spi: spi-s3c64xx: Increase transfer timeout

[Łukasz Stelmach]

Increase timeout by 30 ms for some wiggle room and set the minimum value
to 100 ms. This ensures a non-zero value for short transfers which
may take less than 1 ms. The timeout value does not affect
performance because it is used with a completion.

Similar formula is used in other drivers e.g. sun4i, sun6i.

Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
---
 drivers/spi/spi-s3c64xx.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 0bd3e230350c..9f728a7c59a1 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -473,7 +473,8 @@ static int s3c64xx_wait_for_dma(struct s3c64xx_spi_driver_data *sdd,
 
 	/* millisecs to xfer 'len' bytes @ 'cur_speed' */
 	ms = xfer->len * 8 * 1000 / sdd->cur_speed;
-	ms += 10; /* some tolerance */
+	ms += 30;               /* some tolerance */
+	ms = max(ms, 100);      /* minimum timeout */
 
 	val = msecs_to_jiffies(ms) + 10;
 	val = wait_for_completion_timeout(&sdd->xfer_completion, val);
-- 
2.26.2

[PATCH v3 9/9] spi: spi-s3c64xx: Turn on interrupts upon resume

[Łukasz Stelmach]

s3c64xx_spi_hwinit() disables interrupts. In s3c64xx_spi_probe() after
calling s3c64xx_spi_hwinit() they are enabled with the following call.

Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
---
 drivers/spi/spi-s3c64xx.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
index 9f728a7c59a1..dfa7c91e13aa 100644
--- a/drivers/spi/spi-s3c64xx.c
+++ b/drivers/spi/spi-s3c64xx.c
@@ -1378,6 +1378,10 @@ static int s3c64xx_spi_runtime_resume(struct device *dev)
 
 	s3c64xx_spi_hwinit(sdd);
 
+	writel(S3C64XX_SPI_INT_RX_OVERRUN_EN | S3C64XX_SPI_INT_RX_UNDERRUN_EN |
+	       S3C64XX_SPI_INT_TX_OVERRUN_EN | S3C64XX_SPI_INT_TX_UNDERRUN_EN,
+	       sdd->regs + S3C64XX_SPI_INT_EN);
+
 	return 0;
 
 err_disable_src_clk:
-- 
2.26.2