On 04/04/2023 14:53, James Clark wrote:
child_fwnode should be a read only property based on the DT. If it's
minor nit: Not restricted to DT. This also covers the ACPI.
cleared on the parent device when a child is unloaded, then when the child is loaded again the connection won't be remade.
child_dev should be cleared instead which signifies that the connection should be remade when the child_fwnode registers a new coresight_device.
Similarly the reference count shouldn't be decremented as long as the parent device exists. The correct place to drop the reference is in coresight_release_platform_data() which is already done.
Reproducible on Juno with the following steps:
# load all coresight modules. $ cd /sys/bus/coresight/devices/ $ echo 1 > tmc_etr0/enable_sink $ echo 1 > etm0/enable_source # Works fine ^
$ echo 0 > etm0/enable_source $ rmmod coresight-funnel $ modprobe coresight-funnel $ echo 1 > etm0/enable_source -bash: echo: write error: Invalid argument
Fixes: 37ea1ffddffa ("coresight: Use fwnode handle instead of device names") Fixes: 2af89ebacf29 ("coresight: Clear the connection field properly") Signed-off-by: James Clark james.clark@arm.com
Looks good to me.
Tested-by: Suzuki K Poulose suzuki.poulose@arm.com