On Wed, Nov 10, 2021 at 10:03:38AM +0100, Oleksij Rempel wrote:
> 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>
>
> Do we need to keep this change history? If no, please merge it to the
> first patch.
Yeah, I can do that. It make sense.
Thanks,
-corey
>
> > ---
> > 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;
> > };
> >
> > 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);
> > + hrtimer_forward_now(&i2c_imx->slave_timer, I2C_IMX_CHECK_DELAY);
> > + hrtimer_restart(&i2c_imx->slave_timer);
> > return IRQ_HANDLED;
> > }
> >
> > -static void i2c_imx_slave_timeout(struct timer_list *t)
> > +static enum hrtimer_restart i2c_imx_slave_timeout(struct hrtimer *t)
> > {
> > - struct imx_i2c_struct *i2c_imx = from_timer(i2c_imx, t, slave_timer);
> > + struct imx_i2c_struct *i2c_imx = container_of(t, struct imx_i2c_struct,
> > + slave_timer);
> > unsigned int ctl, status;
> > unsigned long flags;
> >
> > @@ -798,6 +803,7 @@ static void i2c_imx_slave_timeout(struct timer_list *t)
> > ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
> > i2c_imx_slave_handle(i2c_imx, status, ctl);
> > spin_unlock_irqrestore(&i2c_imx->slave_lock, flags);
> > + return HRTIMER_NORESTART;
> > }
> >
> > static void i2c_imx_slave_init(struct imx_i2c_struct *i2c_imx)
> > @@ -1423,7 +1429,8 @@ static int i2c_imx_probe(struct platform_device *pdev)
> > return -ENOMEM;
> >
> > spin_lock_init(&i2c_imx->slave_lock);
> > - timer_setup(&i2c_imx->slave_timer, i2c_imx_slave_timeout, 0);
> > + hrtimer_init(&i2c_imx->slave_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
> > + i2c_imx->slave_timer.function = i2c_imx_slave_timeout;
> >
> > match = device_get_match_data(&pdev->dev);
> > if (match)
> > @@ -1538,7 +1545,7 @@ static int i2c_imx_remove(struct platform_device *pdev)
> > if (ret < 0)
> > return ret;
> >
> > - del_timer_sync(&i2c_imx->slave_timer);
> > + hrtimer_cancel(&i2c_imx->slave_timer);
> >
> > /* remove adapter */
> > dev_dbg(&i2c_imx->adapter.dev, "adapter removed\n");
> > --
> > 2.25.1
> >
> >
>
> --
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