Commit 500c20fe authored Jul 04, 2024 by Wolfram Sang

i2c: add debug message for detected HostNotify alerts



Setting up HostNotify can be tricky. Support debugging by stating
when a HostNotify alert was received independent of the irq being
mapped. Especially useful with the in-kernel i2c testunit. Update
documentation as well.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Andi Shyti <andi.shyti@kernel.org>

parent 71170301

Documentation/i2c/slave-testunit-backend.rst

+5 −0

Original line number	Diff line number	Diff line
		@@ -99,6 +99,11 @@ Example to send a notification after 10ms::

		# i2cset -y 0 0x30 0x02 0x42 0x64 0x01 i

		If the host controller supports HostNotify, this message with debug level
		should appear (Linux 6.11 and later)::

		Detected HostNotify from address 0x30

		0x03 SMBUS_BLOCK_PROC_CALL
		~~~~~~~~~~~~~~~~~~~~~~~~~~

drivers/i2c/i2c-core-base.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -1468,6 +1468,8 @@ int i2c_handle_smbus_host_notify(struct i2c_adapter *adap, unsigned short addr)
		if (!adap)
		return -EINVAL;

		dev_dbg(&adap->dev, "Detected HostNotify from address 0x%02x", addr);

		irq = irq_find_mapping(adap->host_notify_domain, addr);
		if (irq <= 0)
		return -ENXIO;