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Date: Sat, 23 Oct 2021 12:20:41 +0300 From: Oded Gabbay <ogabbay@...nel.org> To: linux-kernel@...r.kernel.org Subject: [PATCH 2/2] habanalabs/gaudi: recover from CPU WD event There are rare cases where the device CPU's watchdog has expired and as a result, the watchdog reset has happened and the CPU will now move to running its preboot f/w. When that happens, the driver will only know that a heartbeat failure occurred. As a result, the driver will send a message to the CPU's main f/w asking it to reset the device, but because the CPU is now running preboot, it won't respond and the re-initialization process will later fail when trying to load the f/w. The solution is to send the request to the preboot as well, only if the reset was caused because of HB failure. Signed-off-by: Oded Gabbay <ogabbay@...nel.org> --- drivers/misc/habanalabs/gaudi/gaudi.c | 20 +++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/drivers/misc/habanalabs/gaudi/gaudi.c b/drivers/misc/habanalabs/gaudi/gaudi.c index 825737dfe381..d2b7ecb45497 100644 --- a/drivers/misc/habanalabs/gaudi/gaudi.c +++ b/drivers/misc/habanalabs/gaudi/gaudi.c @@ -1,7 +1,7 @@ // SPDX-License-Identifier: GPL-2.0 /* - * Copyright 2016-2020 HabanaLabs, Ltd. + * Copyright 2016-2021 HabanaLabs, Ltd. * All Rights Reserved. */ @@ -4296,6 +4296,24 @@ static void gaudi_hw_fini(struct hl_device *hdev, bool hard_reset, bool fw_reset WREG32(irq_handler_offset, gaudi_irq_map_table[GAUDI_EVENT_HALT_MACHINE].cpu_id); + + /* This is a hail-mary attempt to revive the card in the small chance that the + * f/w has experienced a watchdog event, which caused it to return back to preboot. + * In that case, triggering reset through GIC won't help. We need to trigger the + * reset as if Linux wasn't loaded. + * + * We do it only if the reset cause was HB, because that would be the indication + * of such an event. + * + * In case watchdog hasn't expired but we still got HB, then this won't do any + * damage. + */ + if (hdev->curr_reset_cause == HL_RESET_CAUSE_HEARTBEAT) { + if (hdev->asic_prop.hard_reset_done_by_fw) + hl_fw_ask_hard_reset_without_linux(hdev); + else + hl_fw_ask_halt_machine_without_linux(hdev); + } } else { if (hdev->asic_prop.hard_reset_done_by_fw) hl_fw_ask_hard_reset_without_linux(hdev); -- 2.25.1
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