Messages in this thread | | | Date | Tue, 2 Nov 2021 09:58:06 +0100 | From | Uwe Kleine-König <> | Subject | Re: [PATCH 3/3] i2c:imx: Use an hrtimer, not a timer, for checking for bus idle |
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On Mon, Oct 04, 2021 at 07:32:16PM -0500, minyard@acm.org wrote: > From: Corey Minyard <cminyard@mvista.com> > > The timer is too slow and significantly reduces performance. Use an > hrtimer to get things working faster. > > Signed-off-by: Corey Minyard <minyard@acm.org> > Tested-by: Andrew Manley <andrew.manley@sealingtech.com> > Reviewed-by: Andrew Manley <andrew.manley@sealingtech.com> > --- > 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/ | [unhandled content-type:application/pgp-signature] | |