diff mbox series

[net,2/3] ice: reset first in crash dump kernels

Message ID 20231011233334.336092-3-jacob.e.keller@intel.com (mailing list archive)
State Accepted
Commit 0288c3e709e5fabd51e84715c5c798a02f43061a
Delegated to: Netdev Maintainers
Headers show
Series Intel Wired LAN Driver Updates 2023-10-11 (i40e, ice) | expand

Checks

Context Check Description
netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for net
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 1363 this patch: 1363
netdev/cc_maintainers fail 1 blamed authors not CCed: anirudh.venkataramanan@intel.com; 5 maintainers not CCed: intel-wired-lan@lists.osuosl.org pabeni@redhat.com edumazet@google.com anthony.l.nguyen@intel.com anirudh.venkataramanan@intel.com
netdev/build_clang success Errors and warnings before: 1387 this patch: 1387
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 1387 this patch: 1387
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 27 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Jacob Keller Oct. 11, 2023, 11:33 p.m. UTC 
From: Jesse Brandeburg <jesse.brandeburg@intel.com>

When the system boots into the crash dump kernel after a panic, the ice
networking device may still have pending transactions that can cause errors
or machine checks when the device is re-enabled. This can prevent the crash
dump kernel from loading the driver or collecting the crash data.

To avoid this issue, perform a function level reset (FLR) on the ice device
via PCIe config space before enabling it on the crash kernel. This will
clear any outstanding transactions and stop all queues and interrupts.
Restore the config space after the FLR, otherwise it was found in testing
that the driver wouldn't load successfully.

The following sequence causes the original issue:
- Load the ice driver with modprobe ice
- Enable SR-IOV with 2 VFs: echo 2 > /sys/class/net/eth0/device/sriov_num_vfs
- Trigger a crash with echo c > /proc/sysrq-trigger
- Load the ice driver again (or let it load automatically) with modprobe ice
- The system crashes again during pcim_enable_device()

Fixes: 837f08fdecbe ("ice: Add basic driver framework for Intel(R) E800 Series")
Reported-by: Vishal Agrawal <vagrawal@redhat.com>
Reviewed-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
---
 drivers/net/ethernet/intel/ice/ice_main.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index c8286adae946..6550c46e4e36 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -6,6 +6,7 @@ 
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <generated/utsrelease.h>
+#include <linux/crash_dump.h>
 #include "ice.h"
 #include "ice_base.h"
 #include "ice_lib.h"
@@ -5014,6 +5015,20 @@  ice_probe(struct pci_dev *pdev, const struct pci_device_id __always_unused *ent)
 		return -EINVAL;
 	}
 
+	/* when under a kdump kernel initiate a reset before enabling the
+	 * device in order to clear out any pending DMA transactions. These
+	 * transactions can cause some systems to machine check when doing
+	 * the pcim_enable_device() below.
+	 */
+	if (is_kdump_kernel()) {
+		pci_save_state(pdev);
+		pci_clear_master(pdev);
+		err = pcie_flr(pdev);
+		if (err)
+			return err;
+		pci_restore_state(pdev);
+	}
+
 	/* this driver uses devres, see
 	 * Documentation/driver-api/driver-model/devres.rst
 	 */