[PATCH net 1/1] qlcnic: Fix CPU soft lockup while collecting firmware dump

[PATCH net 1/1] qlcnic: Fix CPU soft lockup while collecting firmware dump

[Manish Chopra]

Driver while collecting firmware dump takes longer time to
collect/process some of the firmware dump entries/memories.
Bigger capture masks makes it worse as it results in larger
amount of data being collected and results in CPU soft lockup.
Place cond_resched() in some of the driver flows that are
expectedly time consuming to relinquish the CPU to avoid CPU
soft lockup panic.

Signed-off-by: Shahed Shaikh <shshaikh@marvell.com>
Tested-by: Yonggen Xu <Yonggen.Xu@dell.com>
Signed-off-by: Manish Chopra <manishc@marvell.com>
---
 drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c | 1 +
 drivers/net/ethernet/qlogic/qlcnic/qlcnic_minidump.c  | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c
index a496390b8632..07f9067affc6 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_83xx_init.c
@@ -2043,6 +2043,7 @@ static void qlcnic_83xx_exec_template_cmd(struct qlcnic_adapter *p_dev,
 			break;
 		}
 		entry += p_hdr->size;
+		cond_resched();
 	}
 	p_dev->ahw->reset.seq_index = index;
 }
diff --git a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_minidump.c b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_minidump.c
index afa10a163da1..f34ae8c75bc5 100644
--- a/drivers/net/ethernet/qlogic/qlcnic/qlcnic_minidump.c
+++ b/drivers/net/ethernet/qlogic/qlcnic/qlcnic_minidump.c
@@ -703,6 +703,7 @@ static u32 qlcnic_read_memory_test_agent(struct qlcnic_adapter *adapter,
 		addr += 16;
 		reg_read -= 16;
 		ret += 16;
+		cond_resched();
 	}
 out:
 	mutex_unlock(&adapter->ahw->mem_lock);
@@ -1383,6 +1384,7 @@ int qlcnic_dump_fw(struct qlcnic_adapter *adapter)
 		buf_offset += entry->hdr.cap_size;
 		entry_offset += entry->hdr.offset;
 		buffer = fw_dump->data + buf_offset;
+		cond_resched();
 	}
 
 	fw_dump->clr = 1;
-- 
2.18.1

Re: [PATCH net 1/1] qlcnic: Fix CPU soft lockup while collecting firmware dump

[David Miller]

From: Manish Chopra <manishc@marvell.com>
Date: Wed, 22 Jan 2020 01:43:38 -0800

> Driver while collecting firmware dump takes longer time to
> collect/process some of the firmware dump entries/memories.
> Bigger capture masks makes it worse as it results in larger
> amount of data being collected and results in CPU soft lockup.
> Place cond_resched() in some of the driver flows that are
> expectedly time consuming to relinquish the CPU to avoid CPU
> soft lockup panic.
> 
> Signed-off-by: Shahed Shaikh <shshaikh@marvell.com>
> Tested-by: Yonggen Xu <Yonggen.Xu@dell.com>
> Signed-off-by: Manish Chopra <manishc@marvell.com>

Applied.