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| author | Lu Baolu <baolu.lu@linux.intel.com> | 2025-04-16 10:36:08 +0300 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2025-04-17 17:45:28 +0300 |
| commit | 4f1492efb495bcef34c9ee8a94af81e6cea5abf4 (patch) | |
| tree | 139b2c85d2039d096c73edcc8b45de40e65aeb91 /drivers/fpga/tests/fpga-bridge-test.c | |
| parent | 30a3f2f3e4bd6335b727c83c08a982d969752bc1 (diff) | |
| download | linux-4f1492efb495bcef34c9ee8a94af81e6cea5abf4.tar.xz | |
iommu/vt-d: Revert ATS timing change to fix boot failure
Commit <5518f239aff1> ("iommu/vt-d: Move scalable mode ATS enablement to
probe path") changed the PCI ATS enablement logic to run earlier,
specifically before the default domain attachment.
On some client platforms, this change resulted in boot failures, causing
the kernel to panic with the following message and call trace:
Kernel panic - not syncing: DMAR hardware is malfunctioning
CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.14.0-rc3+ #175
Call Trace:
<TASK>
dump_stack_lvl+0x6f/0xb0
dump_stack+0x10/0x16
panic+0x10a/0x2b7
iommu_enable_translation.cold+0xc/0xc
intel_iommu_init+0xe39/0xec0
? trace_hardirqs_on+0x1e/0xd0
? __pfx_pci_iommu_init+0x10/0x10
pci_iommu_init+0xd/0x40
do_one_initcall+0x5b/0x390
kernel_init_freeable+0x26d/0x2b0
? __pfx_kernel_init+0x10/0x10
kernel_init+0x15/0x120
ret_from_fork+0x35/0x60
? __pfx_kernel_init+0x10/0x10
ret_from_fork_asm+0x1a/0x30
RIP: 1f0f:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0000:0000000000000000 EFLAGS: 841f0f2e66 ORIG_RAX:
1f0f2e6600000000
RAX: 0000000000000000 RBX: 1f0f2e6600000000 RCX:
2e66000000000084
RDX: 0000000000841f0f RSI: 000000841f0f2e66 RDI:
00841f0f2e660000
RBP: 00841f0f2e660000 R08: 00841f0f2e660000 R09:
000000841f0f2e66
R10: 0000000000841f0f R11: 2e66000000000084 R12:
000000841f0f2e66
R13: 0000000000841f0f R14: 2e66000000000084 R15:
1f0f2e6600000000
</TASK>
---[ end Kernel panic - not syncing: DMAR hardware is malfunctioning ]---
Fix this by reverting the timing change for ATS enablement introduced by
the offending commit and restoring the previous behavior.
Fixes: 5518f239aff1 ("iommu/vt-d: Move scalable mode ATS enablement to probe path")
Reported-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Closes: https://lore.kernel.org/linux-iommu/01b9c72f-460d-4f77-b696-54c6825babc9@linux.intel.com/
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Tested-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20250416073608.1799578-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/fpga/tests/fpga-bridge-test.c')
0 files changed, 0 insertions, 0 deletions