On 3/5/2025 11:38 AM, Sudeep Holla wrote: > From: Huisong Li <lihuisong@xxxxxxxxxx> > > The function mbox_chan_received_data() calls the Rx callback of the > mailbox client driver. The callback might set chan_in_use flag from > pcc_send_data(). This flag's status determines whether the PCC channel > is in use. > > However, there is a potential race condition where chan_in_use is > updated incorrectly due to concurrency between the interrupt handler > (pcc_mbox_irq()) and the command sender(pcc_send_data()). > > The 'chan_in_use' flag of a channel is set to true after sending a > command. And the flag of the new command may be cleared erroneous by > the interrupt handler afer mbox_chan_received_data() returns, > > As a result, the interrupt being level triggered can't be cleared in > pcc_mbox_irq() and it will be disabled after the number of handled times > exceeds the specified value. The error log is as follows: > > | kunpeng_hccs HISI04B2:00: PCC command executed timeout! > | kunpeng_hccs HISI04B2:00: get port link status info failed, ret = -110 > | irq 13: nobody cared (try booting with the "irqpoll" option) > | Call trace: > | dump_backtrace+0x0/0x210 > | show_stack+0x1c/0x2c > | dump_stack+0xec/0x130 > | __report_bad_irq+0x50/0x190 > | note_interrupt+0x1e4/0x260 > | handle_irq_event+0x144/0x17c > | handle_fasteoi_irq+0xd0/0x240 > | __handle_domain_irq+0x80/0xf0 > | gic_handle_irq+0x74/0x2d0 > | el1_irq+0xbc/0x140 > | mnt_clone_write+0x0/0x70 > | file_update_time+0xcc/0x160 > | fault_dirty_shared_page+0xe8/0x150 > | do_shared_fault+0x80/0x1d0 > | do_fault+0x118/0x1a4 > | handle_pte_fault+0x154/0x230 > | __handle_mm_fault+0x1ac/0x390 > | handle_mm_fault+0xf0/0x250 > | do_page_fault+0x184/0x454 > | do_translation_fault+0xac/0xd4 > | do_mem_abort+0x44/0xb4 > | el0_da+0x40/0x74 > | el0_sync_handler+0x60/0xb4 > | el0_sync+0x168/0x180 > | handlers: > | pcc_mbox_irq > | Disabling IRQ #13 > > To solve this issue, pcc_mbox_irq() must clear 'chan_in_use' flag before > the call to mbox_chan_received_data(). > > Signed-off-by: Huisong Li <lihuisong@xxxxxxxxxx> > (sudeep.holla: Minor updates to the subject and commit message) > Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx> Tested-by: Robbie King <robbiek@xxxxxxxxxxxxxx>
