[ Upstream commit bd9f5348089b65612e5ca976e2ae22f005340331 ]
I2C core handles the local target for receiving HostNotify alerts. There
is no separate driver bound to that address. That means userspace can
access it if desired, leading to further complications if controllers
are not capable of reading their own local target. Bind the local target
to the dummy driver so it will be marked as "handled by the kernel" if
the HostNotify feature is used. That protects aginst userspace access
and prevents other drivers binding to it.
Fixes: 2a71593da34d ("i2c: smbus: add core function handling SMBus host-notify")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 91811a31b68d3765b3065f4bb6d7d6d84a7cfc9f ]
Baruch reported an OOPS when using the designware controller as target
only. Target-only modes break the assumption of one transfer function
always being available. Fix this by always checking the pointer in
__i2c_transfer.
Reported-by: Baruch Siach <baruch@tkos.co.il>
Closes: https://lore.kernel.org/r/4269631780e5ba789cf1ae391eec1b959def7d99.1712761976.git.baruch@tkos.co.il
Fixes: 4b1acc43331d ("i2c: core changes for slave support")
[wsa: dropped the simplification in core-smbus to avoid theoretical regressions]
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Sasha Levin <sashal@kernel.org>
