diff mbox series

[v4,2/7] i2c: core: Use generic_handle_irq_safe() in i2c_handle_smbus_host_notify().

Message ID 20220211181500.1856198-3-bigeasy@linutronix.de (mailing list archive)
State Accepted
Commit 68ea1b2c3386ad484b7daa4a64fa7b3be661607f
Headers show
Series Provide and use generic_handle_irq_safe() where appropriate. | expand

Commit Message

Sebastian Andrzej Siewior Feb. 11, 2022, 6:14 p.m. UTC 
The i2c-i801 driver invokes i2c_handle_smbus_host_notify() from his
interrupt service routine. On PREEMPT_RT i2c-i801's handler is forced
threaded with enabled interrupts which leads to a warning by
handle_irq_event_percpu() assuming that irq_default_primary_handler()
enabled interrupts.

i2c-i801's interrupt handler can't be made non-threaded because the
interrupt line is shared with other devices.

Use generic_handle_irq_safe() which can invoked with disabled and enabled
interrupts.

Reported-by: Michael Below <below@judiz.de>
Link: https://bugs.debian.org/1002537
Cc: Salvatore Bonaccorso <carnil@debian.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Acked-by: Wolfram Sang <wsa@kernel.org>
---
 drivers/i2c/i2c-core-base.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Wolfram Sang Feb. 23, 2022, 1:21 p.m. UTC | #1 
On Fri, Feb 11, 2022 at 07:14:55PM +0100, Sebastian Andrzej Siewior wrote:
> The i2c-i801 driver invokes i2c_handle_smbus_host_notify() from his
> interrupt service routine. On PREEMPT_RT i2c-i801's handler is forced
> threaded with enabled interrupts which leads to a warning by
> handle_irq_event_percpu() assuming that irq_default_primary_handler()
> enabled interrupts.
> 
> i2c-i801's interrupt handler can't be made non-threaded because the
> interrupt line is shared with other devices.
> 
> Use generic_handle_irq_safe() which can invoked with disabled and enabled
> interrupts.
> 
> Reported-by: Michael Below <below@judiz.de>
> Link: https://bugs.debian.org/1002537
> Cc: Salvatore Bonaccorso <carnil@debian.org>
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> Reviewed-by: Oleksandr Natalenko <oleksandr@natalenko.name>
> Acked-by: Wolfram Sang <wsa@kernel.org>

Is this 5.17 material? Or is 5.18 fine, too?
Sebastian Andrzej Siewior Feb. 25, 2022, 10:26 p.m. UTC | #2 
On 2022-02-23 14:21:32 [+0100], Wolfram Sang wrote:
> Is this 5.17 material? Or is 5.18 fine, too?

5.18 is fine. I intend to push into the RT-stable trees and this can't
be backported without 1/7 and it does not affect !RT so I wouldn't
bother.

Sebastian
Wolfram Sang March 1, 2022, 3:06 p.m. UTC | #3 
On Fri, Feb 25, 2022 at 11:26:46PM +0100, Sebastian Andrzej Siewior wrote:
> On 2022-02-23 14:21:32 [+0100], Wolfram Sang wrote:
> > Is this 5.17 material? Or is 5.18 fine, too?
> 
> 5.18 is fine. I intend to push into the RT-stable trees and this can't
> be backported without 1/7 and it does not affect !RT so I wouldn't
> bother.

Ok, applied to for-next then. Thanks for the heads up!
diff mbox series

Patch

diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 2c59dd748a49f..3f9e5303b6163 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -1424,7 +1424,7 @@  int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr)
 	if (irq <= 0)
 		return -ENXIO;
 
-	generic_handle_irq(irq);
+	generic_handle_irq_safe(irq);
 
 	return 0;
 }