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intel_idle: Disable promotion to C1E on Jasper Lake and Elkhart Lake

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BugLink: https://bugs.launchpad.net/bugs/2077858

PCIe ethernet throughut is sub-optimal on Jasper Lake and Elkhart Lake.

The CPU can take long time to exit to C0 to handle IRQ and perform DMA
when C1E has been entered.

For this reason, adjust intel_idle to disable promotion to C1E and still
use C-states from ACPI _CST on those two platforms.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=219023
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Link: https://patch.msgid.link/20240820041128.102452-1-kai.heng.feng@canonical.com
[ rjw: Subject and changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

(backported from commit 5bb33212b5c664396e5de4cd5a2999abb84a3978 linux-next)
[khfeng: Adjusted for Intel CPU macro change]
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Acked-by: Thibault Ferrante <thibault.ferrante@canonical.com>
Acked-by: Guoqing Jiang <guoqing.jiang@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
This commit is contained in:
Kai-Heng Feng
2024-08-26 10:05:00 +02:00
committed by Stefan Bader
parent f4beab0d51
commit 68d055c07d
1 changed files with 12 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/idle/intel_idle.c
+12 -2
View File
@@ -1475,6 +1475,10 @@ static const struct idle_cpu idle_cpu_dnv __initconst = {
.use_acpi = true,
};
static const struct idle_cpu idle_cpu_tmt __initconst = {
.disable_promotion_to_c1e = true,
};
static const struct idle_cpu idle_cpu_snr __initconst = {
.state_table = snr_cstates,
.disable_promotion_to_c1e = true,
@@ -1538,6 +1542,8 @@ static const struct x86_cpu_id intel_idle_ids[] __initconst = {
X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT, &idle_cpu_bxt),
X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT_PLUS, &idle_cpu_bxt),
X86_MATCH_INTEL_FAM6_MODEL(ATOM_GOLDMONT_D, &idle_cpu_dnv),
X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT, &idle_cpu_tmt),
X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_L, &idle_cpu_tmt),
X86_MATCH_INTEL_FAM6_MODEL(ATOM_TREMONT_D, &idle_cpu_snr),
X86_MATCH_INTEL_FAM6_MODEL(ATOM_CRESTMONT, &idle_cpu_grr),
X86_MATCH_INTEL_FAM6_MODEL(ATOM_CRESTMONT_X, &idle_cpu_srf),
@@ -2074,7 +2080,7 @@ static void __init intel_idle_cpuidle_driver_init(struct cpuidle_driver *drv)
drv->state_count = 1;
if (icpu)
if (icpu && icpu->state_table)
intel_idle_init_cstates_icpu(drv);
else
intel_idle_init_cstates_acpi(drv);
@@ -2208,7 +2214,11 @@ static int __init intel_idle_init(void)
icpu = (const struct idle_cpu *)id->driver_data;
if (icpu) {
cpuidle_state_table = icpu->state_table;
if (icpu->state_table)
cpuidle_state_table = icpu->state_table;
else if (!intel_idle_acpi_cst_extract())
return -ENODEV;
auto_demotion_disable_flags = icpu->auto_demotion_disable_flags;
if (icpu->disable_promotion_to_c1e)
c1e_promotion = C1E_PROMOTION_DISABLE;