On Mon, Oct 04, 2021 at 07:32:16PM -0500, minyard@xxxxxxx wrote:
> From: Corey Minyard <cminyard@xxxxxxxxxx>
>
> The timer is too slow and significantly reduces performance. Use an
> hrtimer to get things working faster.
>
> Signed-off-by: Corey Minyard <minyard@xxxxxxx>
> Tested-by: Andrew Manley <andrew.manley@xxxxxxxxxxxxxxx>
> Reviewed-by: Andrew Manley <andrew.manley@xxxxxxxxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-imx.c | 23 +++++++++++++++--------
> 1 file changed, 15 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
> index 26a04dc0590b..4b0e9d1784dd 100644
> --- a/drivers/i2c/busses/i2c-imx.c
> +++ b/drivers/i2c/busses/i2c-imx.c
> @@ -38,7 +38,7 @@
> #include <linux/iopoll.h>
> #include <linux/kernel.h>
> #include <linux/spinlock.h>
> -#include <linux/timer.h>
> +#include <linux/hrtimer.h>
> #include <linux/module.h>
> #include <linux/of.h>
> #include <linux/of_device.h>
> @@ -53,6 +53,8 @@
> /* This will be the driver name the kernel reports */
> #define DRIVER_NAME "imx-i2c"
>
> +#define I2C_IMX_CHECK_DELAY 30000 /* Time to check for bus idle, in NS */
> +
> /*
> * Enable DMA if transfer byte size is bigger than this threshold.
> * As the hardware request, it must bigger than 4 bytes.\
> @@ -214,8 +216,8 @@ struct imx_i2c_struct {
> enum i2c_slave_event last_slave_event;
>
> /* For checking slave events. */
> - spinlock_t slave_lock;
> - struct timer_list slave_timer;
> + spinlock_t slave_lock;
> + struct hrtimer slave_timer;
This is unrelated to this patch, moreover it was introduced only in
patch 1.
> };
>
> static const struct imx_i2c_hwdata imx1_i2c_hwdata = {
> @@ -783,13 +785,16 @@ static irqreturn_t i2c_imx_slave_handle(struct imx_i2c_struct *i2c_imx,
> }
>
> out:
> - mod_timer(&i2c_imx->slave_timer, jiffies + 1);
> + hrtimer_try_to_cancel(&i2c_imx->slave_timer);
Don't you need to check the return value here?
> + hrtimer_forward_now(&i2c_imx->slave_timer, I2C_IMX_CHECK_DELAY);
> + hrtimer_restart(&i2c_imx->slave_timer);
> return IRQ_HANDLED;
> }
>
Best regards
Uwe
--
Pengutronix e.K. | Uwe Kleine-König |
Industrial Linux Solutions | https://www.pengutronix.de/ |
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