Am 20.02.2017 um 22:22 schrieb Noralf Trønnes:
Den 20.02.2017 20.40, skrev Stefan Wahren:
Hi,
Noralf Trønnes <noralf@xxxxxxxxxxx> hat am 18. Februar 2017 um 19:34
geschrieben:
Den 16.02.2017 22.20, skrev Stefan Wahren:
Since commit e2474541032d ("bcm2835: Fix hang for writing messages
larger than 16 bytes") the interrupt handler is prone to a possible
NULL pointer dereference. This could happen if an interrupt fires
before curr_msg is set by bcm2835_i2c_xfer_msg() and randomly occurs
on the RPi 3. Even this is an unexpected behavior the driver must
handle that with an error instead of a crash.
CC: Noralf Trønnes <noralf@xxxxxxxxxxx>
CC: Martin Sperl <kernel@xxxxxxxxxxxxxxxx>
Reported-by: Peter Robinson <pbrobinson@xxxxxxxxx>
Fixes: e2474541032d ("bcm2835: Fix hang for writing messages larger
than 16 bytes")
Signed-off-by: Stefan Wahren <stefan.wahren@xxxxxxxx>
---
drivers/i2c/busses/i2c-bcm2835.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/i2c/busses/i2c-bcm2835.c
b/drivers/i2c/busses/i2c-bcm2835.c
index c3436f6..10e39c8 100644
--- a/drivers/i2c/busses/i2c-bcm2835.c
+++ b/drivers/i2c/busses/i2c-bcm2835.c
@@ -195,7 +195,9 @@ static irqreturn_t bcm2835_i2c_isr(int
this_irq, void *data)
}
if (val & BCM2835_I2C_S_DONE) {
- if (i2c_dev->curr_msg->flags & I2C_M_RD) {
+ if (!i2c_dev->curr_msg) {
+ dev_err(i2c_dev->dev, "Got unexpected interrupt (from
firmware?)\n");
+ } else if (i2c_dev->curr_msg->flags & I2C_M_RD) {
bcm2835_drain_rxfifo(i2c_dev);
val = bcm2835_i2c_readl(i2c_dev, BCM2835_I2C_S);
}
Thanks,
Acked-by: Noralf Trønnes <noralf@xxxxxxxxxxx>
thanks, but i would be more happier to receive feedback for patches 2
and 3.
I have only worked on dts files downstream and never done any arm64
stuff, so I'm not up to speed on this.
Noralf.
Okay, at the end i only want to know 2 things:
Does new message "Got unexpected interrupt" still appear after applying
all 3 patches?
Does the annoying message "i2c-bcm2835 3f805000.i2c: i2c transfer timed
out" still appear after applying all 3 patches?
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