[PATCH 5.11 500/601] i2c: rcar: make sure irq is not threaded on Gen2 and earlier

Greg Kroah-Hartman
2021-05-12T17:56:22Z

From: Wolfram Sang <wsa+renesas@sang-engineering.com>

[ Upstream commit 24c6d4bc563881539d2cd4433e502436ad87d512 ]

Ensure this irq runs as fast as possible.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/i2c/busses/i2c-rcar.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
index ad6630e3cc77..3c9c3a6f7ac8 100644
--- a/drivers/i2c/busses/i2c-rcar.c
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -928,6 +928,7 @@ static int rcar_i2c_probe(struct platform_device *pdev)
struct rcar_i2c_priv *priv;
struct i2c_adapter *adap;
struct device *dev = &pdev->dev;
+ unsigned long irqflags = 0;
int ret;

/* Otherwise logic will break because some bytes must always use PIO */
@@ -976,6 +977,9 @@ static int rcar_i2c_probe(struct platform_device *pdev)

rcar_i2c_write(priv, ICSAR, 0); /* Gen2: must be 0 if not using slave */

+ if (priv->devtype < I2C_RCAR_GEN3)
+ irqflags |= IRQF_NO_THREAD;
+
if (priv->devtype == I2C_RCAR_GEN3) {
priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
if (!IS_ERR(priv->rstc)) {
@@ -995,7 +999,7 @@ static int rcar_i2c_probe(struct platform_device *pdev)
priv->flags |= ID_P_HOST_NOTIFY;

priv->irq = platform_get_irq(pdev, 0);
- ret = devm_request_irq(dev, priv->irq, rcar_i2c_irq, 0, dev_name(dev), priv);
+ ret = devm_request_irq(dev, priv->irq, rcar_i2c_irq, irqflags, dev_name(dev), priv);
if (ret < 0) {
dev_err(dev, "cannot get irq %d\n", priv->irq);
goto out_pm_disable;
--
2.30.2