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author | Hans de Goede <[email protected]> | 2020-08-09 16:19:01 +0200 |
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committer | Greg Kroah-Hartman <[email protected]> | 2020-08-18 12:07:42 +0200 |
commit | 0ff0705a2ef2929e9326c95df48bdbebb0dafaad (patch) | |
tree | bc5ac50898df1ab67c724e5829582587994ea9ea /tools/perf/scripts/python/export-to-postgresql.py | |
parent | 7a2f2974f26542b4e7b9b4321edb3cbbf3eeb91a (diff) |
usb: typec: ucsi: Fix AB BA lock inversion
Lockdep reports an AB BA lock inversion between ucsi_init() and
ucsi_handle_connector_change():
AB order:
1. ucsi_init takes ucsi->ppm_lock (it runs with that locked for the
duration of the function)
2. usci_init eventually end up calling ucsi_register_displayport,
which takes ucsi_connector->lock
BA order:
1. ucsi_handle_connector_change work is started, takes ucsi_connector->lock
2. ucsi_handle_connector_change calls ucsi_send_command which takes
ucsi->ppm_lock
The ppm_lock really only needs to be hold during 2 functions:
ucsi_reset_ppm() and ucsi_run_command().
This commit fixes the AB BA lock inversion by making ucsi_init drop the
ucsi->ppm_lock before it starts registering ports; and replacing any
ucsi_run_command() calls after this point with ucsi_send_command()
(which is a wrapper around run_command taking the lock while handling
the command).
Some of the replacing of ucsi_run_command with ucsi_send_command
in the helpers used during port registration also fixes a number of
code paths after registration which call ucsi_run_command() without
holding the ppm_lock:
1. ucsi_altmode_update_active() call in ucsi/displayport.c
2. ucsi_register_altmodes() call from ucsi_handle_connector_change()
(through ucsi_partner_change())
Cc: [email protected]
Signed-off-by: Hans de Goede <[email protected]>
Acked-by: Heikki Krogerus <[email protected]>
Reviewed-by: Guenter Roeck <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
Diffstat (limited to 'tools/perf/scripts/python/export-to-postgresql.py')
0 files changed, 0 insertions, 0 deletions