On Thu, Nov 26, 2020 at 02:29:46PM +0100, Sebastian Andrzej Siewior wrote:
From: "Ahmed S. Darwish" <a.darwish@xxxxxxxxxxxxx>
qla4_82xx_rom_lock() spins on a certain hardware state until it is
updated. At the end of each spin, if in_interrupt() is true, it does 20
loops of cpu_relax(). Otherwise, it yields the CPU.
While in_interrupt() is ill-defined and does not provide what the name
suggests, it is not needed here: qla4_82xx_rom_lock() is always called
from process context. Below is an analysis of its callers:
- ql4_nx.c: qla4_82xx_rom_fast_read(), all process context callers:
=> ql4_nx.c: qla4_82xx_pinit_from_rom(), GFP_KERNEL allocation
=> ql4_nx.c: qla4_82xx_load_from_flash(), msleep() in a loop
- ql4_nx.c: qla4_82xx_pinit_from_rom(), earlier discussed
- ql4_nx.c: qla4_82xx_rom_lock_recovery(), bound to "isp_operations"
->rom_lock_recovery() hook, which has one process context caller,
qla4_8xxx_device_bootstrap(), with callers:
=> ql4_83xx.c: qla4_83xx_need_reset_handler(), process, msleep()
=> ql4_nx.c: qla4_8xxx_device_state_handler(), multiple msleep()s
- ql4_nx.c: qla4_82xx_read_flash_data(), has cond_resched()
Remove the in_interrupt() check. Mark, qla4_82xx_rom_lock(), and the
->rom_lock_recovery() hook, with "Context: task, can sleep".
Change qla4_82xx_rom_lock() implementation to sleep 20ms, instead of a
schedule(), for each spin. This is more deterministic, and it matches
the other implementations bound to ->rom_lock_recovery().
Signed-off-by: Ahmed S. Darwish <a.darwish@xxxxxxxxxxxxx>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx>
Cc: Nilesh Javali <njavali@xxxxxxxxxxx>
Cc: Manish Rangankar <mrangankar@xxxxxxxxxxx>
Cc: <GR-QLogic-Storage-Upstream@xxxxxxxxxxx>
Reviewed-by: Daniel Wagner <dwagner@xxxxxxx>
