coresight: cti: Prevent negative values of enable count

Writing 0 to the enable control repeatedly results in a negative value
for enable_req_count. After this, writing 1 to the enable control
appears to not work until the count returns to positive.

Change it so that it's impossible for enable_req_count to be < 0.
Return an error to indicate that the disable request was invalid.

Fixes: 835d722ba10a ("coresight: cti: Initial CoreSight CTI Driver")
Tested-by: Jinlong Mao <[email protected]>
Signed-off-by: James Clark <[email protected]>
Reviewed-by: Mike Leach <[email protected]>
Signed-off-by: Suzuki K Poulose <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

0 files changed, 0 insertions, 0 deletions