| Message ID | 20201119174149.3860883-1-thierry.reding@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | Revert "firmware: QCOM_SCM: Allow qcom_scm driver to be loadable as a permenent module" | expand |
On Thu, Nov 19, 2020 at 06:41:49PM +0100, Thierry Reding wrote: > From: Thierry Reding <treding@nvidia.com> > > Commit d0511b5496c0 ("firmware: QCOM_SCM: Allow qcom_scm driver to be > loadable as a permenent module") causes the ARM SMMU driver to be built > as a loadable module when using the Aarch64 default configuration. This > in turn causes problems because if the loadable module is not shipped > in an initial ramdisk, then the deferred probe timeout mechanism will > cause all SMMU masters to probe without SMMU support and fall back to > just plain DMA ops (not IOMMU-backed). > > Once the system has mounted the rootfs, the ARM SMMU driver will then > be loaded, but since the ARM SMMU driver faults by default, this causes > a slew of SMMU faults for the SMMU masters that have already been set > up with plain DMA ops and cause these devices to malfunction. > > Revert that commit to unbreak things while we look for an alternative > solution. > > Reported-by: Jon Hunter <jonathanh@nvidia.com> > Signed-off-by: Thierry Reding <treding@nvidia.com> > --- > drivers/firmware/Kconfig | 4 ++-- > drivers/firmware/Makefile | 3 +-- > drivers/firmware/qcom_scm.c | 4 ---- > drivers/iommu/Kconfig | 2 -- > drivers/net/wireless/ath/ath10k/Kconfig | 1 - > 5 files changed, 3 insertions(+), 11 deletions(-) Acked-by: Will Deacon <will@kernel.org> John previously agreed to this here: https://lore.kernel.org/r/CALAqxLVDm923WRSB+DVxFacmEtmEPS7Qeq+rW_jbCDMNMWw9PQ@mail.gmail.com so might be worth putting in a Link: tag when it gets applied. Will
On Thu, Nov 19, 2020 at 11:42 AM Thierry Reding <thierry.reding@gmail.com> wrote: > > From: Thierry Reding <treding@nvidia.com> > > Commit d0511b5496c0 ("firmware: QCOM_SCM: Allow qcom_scm driver to be > loadable as a permenent module") causes the ARM SMMU driver to be built > as a loadable module when using the Aarch64 default configuration. This > in turn causes problems because if the loadable module is not shipped > in an initial ramdisk, then the deferred probe timeout mechanism will > cause all SMMU masters to probe without SMMU support and fall back to > just plain DMA ops (not IOMMU-backed). > > Once the system has mounted the rootfs, the ARM SMMU driver will then > be loaded, but since the ARM SMMU driver faults by default, this causes > a slew of SMMU faults for the SMMU masters that have already been set > up with plain DMA ops and cause these devices to malfunction. > FWIW I had the same issues on the Qualcomm platform and merged a patch that turns QCOM_SCM=y in arm64 defconfig earlier today. So this should hide the problem in next linux-next. (And it really should be =y in defconfig regardless of this revert or not). > Revert that commit to unbreak things while we look for an alternative > solution. > I don't fancy the fact that we have a situation where if you're unlucky to have probe deferrals lingering past late initcall things will start to just break and this from a growing number of resource types. But I also don't see any alternatives to fixing the kernel to handle this gracefully. Regards, Bjorn
diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig index 5e369928bc56..3315e3c21586 100644 --- a/drivers/firmware/Kconfig +++ b/drivers/firmware/Kconfig @@ -235,8 +235,8 @@ config INTEL_STRATIX10_RSU Say Y here if you want Intel RSU support. config QCOM_SCM - tristate "Qcom SCM driver" - depends on (ARM && HAVE_ARM_SMCCC) || ARM64 + bool + depends on ARM || ARM64 select RESET_CONTROLLER config QCOM_SCM_DOWNLOAD_MODE_DEFAULT diff --git a/drivers/firmware/Makefile b/drivers/firmware/Makefile index 523173cbff33..5e013b6a3692 100644 --- a/drivers/firmware/Makefile +++ b/drivers/firmware/Makefile @@ -17,8 +17,7 @@ obj-$(CONFIG_ISCSI_IBFT) += iscsi_ibft.o obj-$(CONFIG_FIRMWARE_MEMMAP) += memmap.o obj-$(CONFIG_RASPBERRYPI_FIRMWARE) += raspberrypi.o obj-$(CONFIG_FW_CFG_SYSFS) += qemu_fw_cfg.o -obj-$(CONFIG_QCOM_SCM) += qcom-scm.o -qcom-scm-objs += qcom_scm.o qcom_scm-smc.o qcom_scm-legacy.o +obj-$(CONFIG_QCOM_SCM) += qcom_scm.o qcom_scm-smc.o qcom_scm-legacy.o obj-$(CONFIG_TI_SCI_PROTOCOL) += ti_sci.o obj-$(CONFIG_TRUSTED_FOUNDATIONS) += trusted_foundations.o obj-$(CONFIG_TURRIS_MOX_RWTM) += turris-mox-rwtm.o diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c index 6f431b73e617..7be48c1bec96 100644 --- a/drivers/firmware/qcom_scm.c +++ b/drivers/firmware/qcom_scm.c @@ -1280,7 +1280,6 @@ static const struct of_device_id qcom_scm_dt_match[] = { { .compatible = "qcom,scm" }, {} }; -MODULE_DEVICE_TABLE(of, qcom_scm_dt_match); static struct platform_driver qcom_scm_driver = { .driver = { @@ -1296,6 +1295,3 @@ static int __init qcom_scm_init(void) return platform_driver_register(&qcom_scm_driver); } subsys_initcall(qcom_scm_init); - -MODULE_DESCRIPTION("Qualcomm Technologies, Inc. SCM driver"); -MODULE_LICENSE("GPL v2"); diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index c64d7a2b6513..04878caf6da4 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -248,7 +248,6 @@ config SPAPR_TCE_IOMMU config ARM_SMMU tristate "ARM Ltd. System MMU (SMMU) Support" depends on ARM64 || ARM || (COMPILE_TEST && !GENERIC_ATOMIC64) - depends on QCOM_SCM || !QCOM_SCM #if QCOM_SCM=m this can't be =y select IOMMU_API select IOMMU_IO_PGTABLE_LPAE select ARM_DMA_USE_IOMMU if ARM @@ -376,7 +375,6 @@ config QCOM_IOMMU # Note: iommu drivers cannot (yet?) be built as modules bool "Qualcomm IOMMU Support" depends on ARCH_QCOM || (COMPILE_TEST && !GENERIC_ATOMIC64) - depends on QCOM_SCM=y select IOMMU_API select IOMMU_IO_PGTABLE_LPAE select ARM_DMA_USE_IOMMU diff --git a/drivers/net/wireless/ath/ath10k/Kconfig b/drivers/net/wireless/ath/ath10k/Kconfig index 741289e385d5..40f91bc8514d 100644 --- a/drivers/net/wireless/ath/ath10k/Kconfig +++ b/drivers/net/wireless/ath/ath10k/Kconfig @@ -44,7 +44,6 @@ config ATH10K_SNOC tristate "Qualcomm ath10k SNOC support" depends on ATH10K depends on ARCH_QCOM || COMPILE_TEST - depends on QCOM_SCM || !QCOM_SCM #if QCOM_SCM=m this can't be =y select QCOM_QMI_HELPERS help This module adds support for integrated WCN3990 chip connected