| Message ID | 20190805123134.23199-1-huangfq.daxian@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | i2c: avoid sleep in IRQ context | expand |
Adamski, Krzysztof (Nokia - PL/Wroclaw) <krzysztof.adamski@nokia.com> 於 2019年8月7日週三 下午2:51寫道： > > On Mon, Aug 05, 2019 at 08:31:34PM +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. > > > >Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com> > >--- > > drivers/i2c/busses/i2c-pxa.c | 2 ++ > > 1 file changed, 2 insertions(+) > > > >diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c > >index 2c3c3d6935c0..b35a0e8efcb2 100644 > >--- a/drivers/i2c/busses/i2c-pxa.c > >+++ b/drivers/i2c/busses/i2c-pxa.c > >@@ -443,6 +443,8 @@ static int i2c_pxa_wait_slave(struct pxa_i2c *i2c) > > > > show_state(i2c); > > > >+ if (in_interrupt()) > >+ return 0; > > Sleeping in irq context is not good indeed but if you just return here, > an error will be printed from i2c_pxa_set_slave() and cleanup of ICR > will be skipped. Is that ok? Sorry for this mistake. Maybe it should be changed to mdelay. And the new patch is like this: if (in_interrupt()) { mdelay(1); } else { msleep(1); } > > > while (time_before(jiffies, timeout)) { > > if (i2c_debug > 1) > > dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n", >
diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c index 2c3c3d6935c0..b35a0e8efcb2 100644 --- a/drivers/i2c/busses/i2c-pxa.c +++ b/drivers/i2c/busses/i2c-pxa.c @@ -443,6 +443,8 @@ static int i2c_pxa_wait_slave(struct pxa_i2c *i2c) show_state(i2c); + if (in_interrupt()) + return 0; while (time_before(jiffies, timeout)) { if (i2c_debug > 1) dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
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. Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com> --- drivers/i2c/busses/i2c-pxa.c | 2 ++ 1 file changed, 2 insertions(+)