On 09/11/23 13:20, Hanjun Guo wrote:
External email: Use caution opening links or attachments
On 2023/10/20 16:30, Sumit Gupta wrote:
Current implementation of processor_thermal performs software
throttling
in fixed steps of "20%" which can be too coarse for some platforms.
We observed some performance gain after reducing the throttle
percentage.
Change the CPUFREQ thermal reduction percentage and maximum thermal
steps
to be configurable. Also, update the default values of both for Nvidia
Tegra241 (Grace) SoC. The thermal reduction percentage is reduced to
"5%"
and accordingly the maximum number of thermal steps are increased as
they
are derived from the reduction percentage.
Signed-off-by: Srikar Srimath Tirumala <srikars@xxxxxxxxxx>
Co-developed-by: Sumit Gupta <sumitg@xxxxxxxxxx>
Signed-off-by: Sumit Gupta <sumitg@xxxxxxxxxx>
---
drivers/acpi/arm64/Makefile | 1 +
drivers/acpi/arm64/thermal_cpufreq.c | 20 ++++++++++++++++
drivers/acpi/processor_thermal.c | 35
+++++++++++++++++++++++++---
include/linux/acpi.h | 9 +++++++
4 files changed, 62 insertions(+), 3 deletions(-)
create mode 100644 drivers/acpi/arm64/thermal_cpufreq.c
diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile
index 143debc1ba4a..3f181d8156cc 100644
--- a/drivers/acpi/arm64/Makefile
+++ b/drivers/acpi/arm64/Makefile
@@ -5,3 +5,4 @@ obj-$(CONFIG_ACPI_GTDT) += gtdt.o
obj-$(CONFIG_ACPI_APMT) += apmt.o
obj-$(CONFIG_ARM_AMBA) += amba.o
obj-y += dma.o init.o
+obj-$(CONFIG_ACPI) += thermal_cpufreq.o
diff --git a/drivers/acpi/arm64/thermal_cpufreq.c
b/drivers/acpi/arm64/thermal_cpufreq.c
new file mode 100644
index 000000000000..de834fb013e7
--- /dev/null
+++ b/drivers/acpi/arm64/thermal_cpufreq.c
@@ -0,0 +1,20 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/acpi.h>
+
+#ifdef CONFIG_HAVE_ARM_SMCCC_DISCOVERY
+#define SMCCC_SOC_ID_T241 0x036b0241
+
+int acpi_thermal_cpufreq_pctg(void)
+{
+ s32 soc_id = arm_smccc_get_soc_id_version();
+
+ /*
+ * Check JEP106 code for NVIDIA Tegra241 chip (036b:0241) and
+ * reduce the CPUFREQ Thermal reduction percentage to 5%.
+ */
+ if (soc_id == SMCCC_SOC_ID_T241)
+ return 5;
+
+ return 0;
+}
+#endif
This part needs an ACK from the ARM folks.
Sorry, missed adding 'ACPI arm64' maintainers. Added Lorenzo, Sudeep and
Hanjun.
Sorry for the late reply, would mind giving me the link which the ID
(SMCCC_SOC_ID_T241) is documented?
Thanks
Hanjun
The ID is already used in file 'irq-gic-v3.c'. Please refer change [1].
[1]
https://lore.kernel.org/linux-arm-kernel/20230319024314.3540573-2-sdonthineni@xxxxxxxxxx/
Best Regards,
Sumit Gupta
