[PATCH 6.18 058/752] powercap: intel_rapl: Add PL4 support for Ice Lake

Sasha Levin
2026-02-28T17:48:57Z

From: Daniel Tang <danielzgtg.opensource@gmail.com>

[ Upstream commit 54b3cd55a515c7c0fcfa0c1f0b10d62c11d64bcc ]

Microsoft Surface Pro 7 firmware throttles the processor upon
boot/resume. Userspace needs to be able to restore the correct value.

Link: https://github.com/linux-surface/linux-surface/issues/706
Signed-off-by: Daniel Tang <danielzgtg.opensource@gmail.com>
Link: https://patch.msgid.link/6088605.ChMirdbgyp@daniel-desktop3
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/powercap/intel_rapl_msr.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/powercap/intel_rapl_msr.c b/drivers/powercap/intel_rapl_msr.c
index c6b9a7debc354..e827247683dbf 100644
--- a/drivers/powercap/intel_rapl_msr.c
+++ b/drivers/powercap/intel_rapl_msr.c
@@ -140,6 +140,7 @@ static int rapl_msr_write_raw(int cpu, struct reg_action *ra)

/* List of verified CPUs. */
static const struct x86_cpu_id pl4_support_ids[] = {
+ X86_MATCH_VFM(INTEL_ICELAKE_L, NULL),
X86_MATCH_VFM(INTEL_TIGERLAKE_L, NULL),
X86_MATCH_VFM(INTEL_ALDERLAKE, NULL),
X86_MATCH_VFM(INTEL_ALDERLAKE_L, NULL),
--
2.51.0