[v2] Add Mobileye EyeQ5 support to the Nomadik I2C controller & use hrtimers for timeouts

[PATCH v2 07/11] i2c: nomadik: replace jiffies by ktime for FIFO flushing timeout

Posted by Théo Lebrun 1 year, 11 months ago

The FIFO flush function uses a jiffies amount to detect timeouts as the
flushing is async. Replace with ktime to get more accurate precision
and support short timeouts.

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
---
 drivers/i2c/busses/i2c-nomadik.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/i2c/busses/i2c-nomadik.c b/drivers/i2c/busses/i2c-nomadik.c
index e68b8e0d7919..afd54999bbbb 100644
--- a/drivers/i2c/busses/i2c-nomadik.c
+++ b/drivers/i2c/busses/i2c-nomadik.c
@@ -219,8 +219,8 @@ static inline void i2c_clr_bit(void __iomem *reg, u32 mask)
 static int flush_i2c_fifo(struct nmk_i2c_dev *priv)
 {
 #define LOOP_ATTEMPTS 10
+	ktime_t timeout;
 	int i;
-	unsigned long timeout;
 
 	/*
 	 * flush the transmit and receive FIFO. The flushing
@@ -232,9 +232,9 @@ static int flush_i2c_fifo(struct nmk_i2c_dev *priv)
 	writel((I2C_CR_FTX | I2C_CR_FRX), priv->virtbase + I2C_CR);
 
 	for (i = 0; i < LOOP_ATTEMPTS; i++) {
-		timeout = jiffies + priv->adap.timeout;
+		timeout = ktime_add_us(ktime_get(), priv->timeout_usecs);
 
-		while (!time_after(jiffies, timeout)) {
+		while (ktime_after(timeout, ktime_get())) {
 			if ((readl(priv->virtbase + I2C_CR) &
 				(I2C_CR_FTX | I2C_CR_FRX)) == 0)
 				return 0;

-- 
2.44.0

Re: [PATCH v2 07/11] i2c: nomadik: replace jiffies by ktime for FIFO flushing timeout

Posted by Andi Shyti 1 year, 11 months ago

Hi Theo,

On Thu, Feb 29, 2024 at 07:10:55PM +0100, Théo Lebrun wrote:
> The FIFO flush function uses a jiffies amount to detect timeouts as the
> flushing is async. Replace with ktime to get more accurate precision
> and support short timeouts.
> 
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>

Reviewed-by: Andi Shyti <andi.shyti@kernel.org>

Thanks,
Andi

Re: [PATCH v2 07/11] i2c: nomadik: replace jiffies by ktime for FIFO flushing timeout

Posted by Wolfram Sang 1 year, 11 months ago

On Thu, Feb 29, 2024 at 07:10:55PM +0100, Théo Lebrun wrote:
> The FIFO flush function uses a jiffies amount to detect timeouts as the
> flushing is async. Replace with ktime to get more accurate precision
> and support short timeouts.
> 
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>

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