spi: spi-mt65xx: Use threaded interrupt for non-SPIMEM transfer

Commit Message

AngeloGioacchino Del Regno July 26, 2024, 11:47 a.m. UTC

In order to avoid blocking for an excessive amount of time, eventually
impacting on system responsiveness, interrupt handlers should finish
executing in as little time as possible.

Use threaded interrupt and move the SPI transfer handling (both
CPU and DMA) for the non-spimem case to an interrupt thread instead.

For SPI-MEM (IPM) controllers, handling is kept in the blocking
interrupt as it simply consists in signalling completion.

Signed-off-by: AngeloGioacchino Del Regno <[e-mail]>
---
 drivers/spi/spi-mt65xx.c | 40 +++++++++++++++++++++++++---------------
 1 file changed, 25 insertions(+), 15 deletions(-)

Comments

Mark Brown July 29, 2024, 3:40 p.m. UTC | #1

On Fri, 26 Jul 2024 13:47:21 +0200, AngeloGioacchino Del Regno wrote:
> In order to avoid blocking for an excessive amount of time, eventually
> impacting on system responsiveness, interrupt handlers should finish
> executing in as little time as possible.
> 
> Use threaded interrupt and move the SPI transfer handling (both
> CPU and DMA) for the non-spimem case to an interrupt thread instead.
> 
> [...]

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: spi-mt65xx: Use threaded interrupt for non-SPIMEM transfer
      commit: 5972eb05ca322bb1efe44d32808bc7a331e7aee4

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark

Patch

diff --git a/drivers/spi/spi-mt65xx.c b/drivers/spi/spi-mt65xx.c
index 36c2f52cd6b8..dfee244fc317 100644
--- a/drivers/spi/spi-mt65xx.c
+++ b/drivers/spi/spi-mt65xx.c
@@ -743,25 +743,13 @@  static int mtk_spi_setup(struct spi_device *spi)
 	return 0;
 }
 
-static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
+static irqreturn_t mtk_spi_interrupt_thread(int irq, void *dev_id)
 {
 	u32 cmd, reg_val, cnt, remainder, len;
 	struct spi_controller *host = dev_id;
 	struct mtk_spi *mdata = spi_controller_get_devdata(host);
 	struct spi_transfer *xfer = mdata->cur_transfer;
 
-	reg_val = readl(mdata->base + SPI_STATUS0_REG);
-	if (reg_val & MTK_SPI_PAUSE_INT_STATUS)
-		mdata->state = MTK_SPI_PAUSED;
-	else
-		mdata->state = MTK_SPI_IDLE;
-
-	/* SPI-MEM ops */
-	if (mdata->use_spimem) {
-		complete(&mdata->spimem_done);
-		return IRQ_HANDLED;
-	}
-
 	if (!host->can_dma(host, NULL, xfer)) {
 		if (xfer->rx_buf) {
 			cnt = mdata->xfer_len / 4;
@@ -845,6 +833,27 @@  static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
 	return IRQ_HANDLED;
 }
 
+static irqreturn_t mtk_spi_interrupt(int irq, void *dev_id)
+{
+	struct spi_controller *host = dev_id;
+	struct mtk_spi *mdata = spi_controller_get_devdata(host);
+	u32 reg_val;
+
+	reg_val = readl(mdata->base + SPI_STATUS0_REG);
+	if (reg_val & MTK_SPI_PAUSE_INT_STATUS)
+		mdata->state = MTK_SPI_PAUSED;
+	else
+		mdata->state = MTK_SPI_IDLE;
+
+	/* SPI-MEM ops */
+	if (mdata->use_spimem) {
+		complete(&mdata->spimem_done);
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_WAKE_THREAD;
+}
+
 static int mtk_spi_mem_adjust_op_size(struct spi_mem *mem,
 				      struct spi_mem_op *op)
 {
@@ -1255,8 +1264,9 @@  static int mtk_spi_probe(struct platform_device *pdev)
 		dev_notice(dev, "SPI dma_set_mask(%d) failed, ret:%d\n",
 			   addr_bits, ret);
 
-	ret = devm_request_irq(dev, irq, mtk_spi_interrupt,
-			       IRQF_TRIGGER_NONE, dev_name(dev), host);
+	ret = devm_request_threaded_irq(dev, irq, mtk_spi_interrupt,
+					mtk_spi_interrupt_thread,
+					IRQF_TRIGGER_NONE, dev_name(dev), host);
 	if (ret)
 		return dev_err_probe(dev, ret, "failed to register irq\n");