* [PATCH v2] i2c: avoid sleep in IRQ context
@ 2019-08-07 7:18 Fuqian Huang
2019-08-14 10:07 ` Wolfram Sang
0 siblings, 1 reply; 2+ messages in thread
From: Fuqian Huang @ 2019-08-07 7:18 UTC (permalink / raw)
Cc: Greg Kroah-Hartman, linux-i2c, linux-kernel, Fuqian Huang
i2c_pxa_handler -> i2c_pxa_irq_txempty ->
i2c_pxa_reset -> i2c_pxa_set_slave -> i2c_pxa_wait_slave
As i2c_pxa_handler is an interrupt handler, it will finally
calls i2c_pxa_wait_slave which calls msleep.
Add in_interrupt check before msleep to avoid sleep
in IRQ context.
When in interrupt context, use mdelay instead of msleep.
Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
---
drivers/i2c/busses/i2c-pxa.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index 2c3c3d6935c0..876e693bafd9 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -456,7 +456,10 @@ static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
return 1;
}
- msleep(1);
+ if (in_interrupt())
+ mdelay(1);
+ else
+ msleep(1);
}
if (i2c_debug > 0)
--
2.11.0
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] i2c: avoid sleep in IRQ context
2019-08-07 7:18 [PATCH v2] i2c: avoid sleep in IRQ context Fuqian Huang
@ 2019-08-14 10:07 ` Wolfram Sang
0 siblings, 0 replies; 2+ messages in thread
From: Wolfram Sang @ 2019-08-14 10:07 UTC (permalink / raw)
To: Fuqian Huang, Russell King; +Cc: Greg Kroah-Hartman, linux-i2c, linux-kernel
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On Wed, Aug 07, 2019 at 03:18:07PM +0800, Fuqian Huang wrote:
> i2c_pxa_handler -> i2c_pxa_irq_txempty ->
> i2c_pxa_reset -> i2c_pxa_set_slave -> i2c_pxa_wait_slave
>
> As i2c_pxa_handler is an interrupt handler, it will finally
> calls i2c_pxa_wait_slave which calls msleep.
>
> Add in_interrupt check before msleep to avoid sleep
> in IRQ context.
> When in interrupt context, use mdelay instead of msleep.
>
> Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Adding RMK to CC because he is the PXA I2C slave user I know of.
> ---
> drivers/i2c/busses/i2c-pxa.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
> index 2c3c3d6935c0..876e693bafd9 100644
> --- a/drivers/i2c/busses/i2c-pxa.c
> +++ b/drivers/i2c/busses/i2c-pxa.c
> @@ -456,7 +456,10 @@ static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
> return 1;
> }
>
> - msleep(1);
> + if (in_interrupt())
> + mdelay(1);
> + else
> + msleep(1);
> }
>
> if (i2c_debug > 0)
> --
> 2.11.0
>
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