linux-kernel - [PATCH v3 04/11] ACPI: CPPC: Drop check for non zero perf ratio

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Message-ID: <20240905163007.1350840-5-superm1@kernel.org>
Date: Thu,  5 Sep 2024 11:30:00 -0500
From: Mario Limonciello <superm1@...nel.org>
To: "Gautham R . Shenoy" <gautham.shenoy@....com>,
	Perry Yuan <perry.yuan@....com>
Cc: Borislav Petkov <bp@...en8.de>,
	x86@...nel.org (maintainer:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
	"Rafael J . Wysocki" <rafael@...nel.org>,
	linux-kernel@...r.kernel.org (open list:X86 ARCHITECTURE (32-BIT AND 64-BIT)),
	linux-acpi@...r.kernel.org (open list:ACPI),
	linux-pm@...r.kernel.org (open list:CPU FREQUENCY SCALING FRAMEWORK),
	Mario Limonciello <mario.limonciello@....com>,
	"Gautham R . Shenoy" <gautham.sheoy@....com>
Subject: [PATCH v3 04/11] ACPI: CPPC: Drop check for non zero perf ratio

From: Mario Limonciello <mario.limonciello@....com>

perf_ratio is a u64 and SCHED_CAPACITY_SCALE is a large number.
Shifting by one will never have a zero value.

Drop the check.

Suggested-by: Gautham R. Shenoy <gautham.shenoy@....com>
Reviewed-by: Gautham R. Shenoy <gautham.sheoy@....com>
Signed-off-by: Mario Limonciello <mario.limonciello@....com>
---
v2->v3:
 * Correct typo in commit message
 * Pick up tag
---
 arch/x86/kernel/acpi/cppc.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/arch/x86/kernel/acpi/cppc.c b/arch/x86/kernel/acpi/cppc.c
index 660cfeb6384ba..e65c77afab318 100644
--- a/arch/x86/kernel/acpi/cppc.c
+++ b/arch/x86/kernel/acpi/cppc.c
@@ -91,13 +91,8 @@ static void amd_set_max_freq_ratio(void)
 		return;
 	}
 
-	perf_ratio = div_u64(numerator * SCHED_CAPACITY_SCALE, nominal_perf);
 	/* midpoint between max_boost and max_P */
-	perf_ratio = (perf_ratio + SCHED_CAPACITY_SCALE) >> 1;
-	if (!perf_ratio) {
-		pr_debug("Non-zero highest/nominal perf values led to a 0 ratio\n");
-		return;
-	}
+	perf_ratio = (div_u64(numerator * SCHED_CAPACITY_SCALE, nominal_perf) + SCHED_CAPACITY_SCALE) >> 1;
 
 	freq_invariance_set_perf_ratio(perf_ratio, false);
 }
-- 
2.43.0