Skip to content
Commit 72124f07 authored by Richard Fitzgerald's avatar Richard Fitzgerald Committed by Vinod Koul
Browse files

soundwire: bus: Don't exit early if no device IDs were programmed



Only exit sdw_handle_slave_status() right after calling
sdw_program_device_num() if it actually programmed an ID into at
least one device.

sdw_handle_slave_status() should protect itself against phantom
device #0 ATTACHED indications. In that case there is no actual
device still on #0. The early exit relies on there being a status
change to ATTACHED on the reprogrammed device to trigger another
call to sdw_handle_slave_status() which will then handle the status
of all peripherals. If no device was actually programmed with an
ID there won't be a new ATTACHED indication. This can lead to the
status of other peripherals not being handled.

The status passed to sdw_handle_slave_status() is obviously always
from a point of time in the past, and may indicate accumulated
unhandled events (depending how the bus manager operates). It's
possible that a device ID is reprogrammed but the last PING status
captured state just before that, when it was still reporting on
ID #0. Then sdw_handle_slave_status() is called with this PING info,
just before a new PING status is available showing it now on its new
ID. So sdw_handle_slave_status() will receive a phantom report of a
device on #0, but it will not find one.

Signed-off-by: default avatarRichard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: default avatarPierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20220914160248.1047627-6-rf@opensource.cirrus.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 0c5e99c4
Loading
Loading
Loading
Loading
0% Loading or .
You are about to add 0 people to the discussion. Proceed with caution.
Please to comment