linux-kernel - [PATCH] drm/radeon: remove dead code in ni_mc_load

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Date: Wed, 17 Jan 2024 06:44:36 -0800
From: Nikita Zhandarovich <n.zhandarovich@...tech.ru>
To: Alex Deucher <alexander.deucher@....com>
CC: Nikita Zhandarovich <n.zhandarovich@...tech.ru>,
	Christian König <christian.koenig@....com>, "Pan, Xinhui"
	<Xinhui.Pan@....com>, David Airlie <airlied@...il.com>, Daniel Vetter
	<daniel@...ll.ch>, <amd-gfx@...ts.freedesktop.org>,
	<dri-devel@...ts.freedesktop.org>, <linux-kernel@...r.kernel.org>,
	<lvc-project@...uxtesting.org>
Subject: [PATCH] drm/radeon: remove dead code in ni_mc_load_microcode()

Inside the if block with (running == 0), the checks for 'running'
possibly being non-zero are redundant. Remove them altogether.

This change is similar to the one authored by Heinrich Schuchardt
<xypron.glpk@....de> in commit
ddbbd3be9679 ("drm/radeon: remove dead code, si_mc_load_microcode (v2)")

Found by Linux Verification Center (linuxtesting.org) with static
analysis tool Svace.

Fixes: 0af62b016804 ("drm/radeon/kms: add ucode loader for NI")
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@...tech.ru>
---
 drivers/gpu/drm/radeon/ni.c | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/radeon/ni.c b/drivers/gpu/drm/radeon/ni.c
index 927e5f42e97d..8eac8c090433 100644
--- a/drivers/gpu/drm/radeon/ni.c
+++ b/drivers/gpu/drm/radeon/ni.c
@@ -624,7 +624,7 @@ static const u32 cayman_io_mc_regs[BTC_IO_MC_REGS_SIZE][2] = {
 int ni_mc_load_microcode(struct radeon_device *rdev)
 {
 	const __be32 *fw_data;
-	u32 mem_type, running, blackout = 0;
+	u32 mem_type, running;
 	u32 *io_mc_regs;
 	int i, ucode_size, regs_size;
 
@@ -659,11 +659,6 @@ int ni_mc_load_microcode(struct radeon_device *rdev)
 	running = RREG32(MC_SEQ_SUP_CNTL) & RUN_MASK;
 
 	if ((mem_type == MC_SEQ_MISC0_GDDR5_VALUE) && (running == 0)) {
-		if (running) {
-			blackout = RREG32(MC_SHARED_BLACKOUT_CNTL);
-			WREG32(MC_SHARED_BLACKOUT_CNTL, 1);
-		}
-
 		/* reset the engine and set to writable */
 		WREG32(MC_SEQ_SUP_CNTL, 0x00000008);
 		WREG32(MC_SEQ_SUP_CNTL, 0x00000010);
@@ -689,9 +684,6 @@ int ni_mc_load_microcode(struct radeon_device *rdev)
 				break;
 			udelay(1);
 		}
-
-		if (running)
-			WREG32(MC_SHARED_BLACKOUT_CNTL, blackout);
 	}
 
 	return 0;