Changing force_stage dynamically isn't supported by the driver and it also doesn't make a whole lot of sense to change it once the SMMU is up and running.
This patch makes the sysfs entry for the parameter read-only. Signed-off-by: Will Deacon <will.dea...@arm.com> --- drivers/iommu/arm-smmu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index e2a788eea5ed..dce041b1c139 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -246,7 +246,7 @@ #define FSYNR0_WNR (1 << 4) static int force_stage; -module_param_named(force_stage, force_stage, int, S_IRUGO | S_IWUSR); +module_param_named(force_stage, force_stage, int, S_IRUGO); MODULE_PARM_DESC(force_stage, "Force SMMU mappings to be installed at a particular stage of translation. A value of '1' or '2' forces the corresponding stage. All other values are ignored (i.e. no stage is forced). Note that selecting a specific stage will disable support for nested translation."); -- 2.1.4 _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu