iommu/amd: Increase timeout waiting for GA log enablement

On some systems it can take a long time for the hardware to enable the
GA log of the AMD IOMMU. The current wait time is only 0.1ms, but
testing showed that it can take up to 14ms for the GA log to enter
running state after it has been enabled.

Sometimes the long delay happens when booting the system, sometimes
only on resume. Adjust the timeout accordingly to not print a warning
when hardware takes a longer than usual.

There has already been an attempt to fix this with commit

	9b45a7738eec ("iommu/amd: Fix loop timeout issue in iommu_ga_log_enable()")

But that commit was based on some wrong math and did not fix the issue
in all cases.

Cc: "D. Ziegfeld" <dzigg@posteo.de>
Cc: Jörg-Volker Peetz <jvpeetz@web.de>
Fixes: 8bda0cfbdc1a ("iommu/amd: Detect and initialize guest vAPIC log")
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20220520102214.12563-1-joro@8bytes.org

diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 648d6b94ba8cca3051886840a8cd006fd095c876..b69f6ab440dcf79a5f09395b921faf421bd19c91 100644 (file)
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -84,7 +84,7 @@
 #define ACPI_DEVFLAG_LINT1              0x80
 #define ACPI_DEVFLAG_ATSDIS             0x10000000
 
-#define LOOP_TIMEOUT   100000
+#define LOOP_TIMEOUT   2000000
 /*
  * ACPI table definitions
  *