linux-kernel - [PATCH v3 3/6] drivers/thermal/exynos: improve sanitize_temp

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240807084829.1037303-4-m.majewski2@samsung.com>
Date: Wed,  7 Aug 2024 10:48:22 +0200
From: Mateusz Majewski <m.majewski2@...sung.com>
To: linux-pm@...r.kernel.org, linux-samsung-soc@...r.kernel.org,
	devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org
Cc: Mateusz Majewski <m.majewski2@...sung.com>, Bartlomiej Zolnierkiewicz
	<bzolnier@...il.com>, Krzysztof Kozlowski <krzk@...nel.org>, "Rafael J.
 Wysocki" <rafael@...nel.org>, Daniel Lezcano <daniel.lezcano@...aro.org>,
	Zhang Rui <rui.zhang@...el.com>, Lukasz Luba <lukasz.luba@....com>, Rob
	Herring <robh@...nel.org>, Conor Dooley <conor+dt@...nel.org>, Alim Akhtar
	<alim.akhtar@...sung.com>, Sam Protsenko <semen.protsenko@...aro.org>, Anand
	Moon <linux.amoon@...il.com>
Subject: [PATCH v3 3/6] drivers/thermal/exynos: improve sanitize_temp_error

There are two minor issues regarding this function.

One is that it attempts to calculate the second calibration value even
if 1-point trimming is being used; in this case, the calculated value is
probably not useful and is never used anyway. Changing this also
requires a minor reordering in Exynos5433 initialization function, so
that we know which type of trimming is used before we call
sanitize_temp_error.

The second issue is that the function is not very consistent when it
comes to the use of Exynos7-specific parameters. This seems to not be an
issue in practice, in part because some of these issues are related to
the mentioned calculation of the second calibration value. However,
fixing this makes the code a bit less confusing, and will be required
for Exynos850 which has 9-bit temperature values and uses 2-point
trimming.

Reviewed-by: Sam Protsenko <semen.protsenko@...aro.org>
Signed-off-by: Mateusz Majewski <m.majewski2@...sung.com>
---
v1 -> v2: reworked to change shift instead of only mask and to also fix
  the 2-point trimming issue.

 drivers/thermal/samsung/exynos_tmu.c | 23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

diff --git a/drivers/thermal/samsung/exynos_tmu.c b/drivers/thermal/samsung/exynos_tmu.c
index b68e9755c933..087a09628e23 100644
--- a/drivers/thermal/samsung/exynos_tmu.c
+++ b/drivers/thermal/samsung/exynos_tmu.c
@@ -111,6 +111,7 @@
 #define EXYNOS7_TMU_REG_EMUL_CON		0x160
 
 #define EXYNOS7_TMU_TEMP_MASK			0x1ff
+#define EXYNOS7_TMU_TEMP_SHIFT			9
 #define EXYNOS7_PD_DET_EN_SHIFT			23
 #define EXYNOS7_TMU_INTEN_RISE0_SHIFT		0
 #define EXYNOS7_EMUL_DATA_SHIFT			7
@@ -234,20 +235,23 @@ static void sanitize_temp_error(struct exynos_tmu_data *data, u32 trim_info)
 	u16 tmu_temp_mask =
 		(data->soc == SOC_ARCH_EXYNOS7) ? EXYNOS7_TMU_TEMP_MASK
 						: EXYNOS_TMU_TEMP_MASK;
+	int tmu_85_shift =
+		(data->soc == SOC_ARCH_EXYNOS7) ? EXYNOS7_TMU_TEMP_SHIFT
+						: EXYNOS_TRIMINFO_85_SHIFT;
 
 	data->temp_error1 = trim_info & tmu_temp_mask;
-	data->temp_error2 = ((trim_info >> EXYNOS_TRIMINFO_85_SHIFT) &
-				EXYNOS_TMU_TEMP_MASK);
-
 	if (!data->temp_error1 ||
 	    (data->min_efuse_value > data->temp_error1) ||
 	    (data->temp_error1 > data->max_efuse_value))
-		data->temp_error1 = data->efuse_value & EXYNOS_TMU_TEMP_MASK;
+		data->temp_error1 = data->efuse_value & tmu_temp_mask;
 
-	if (!data->temp_error2)
-		data->temp_error2 =
-			(data->efuse_value >> EXYNOS_TRIMINFO_85_SHIFT) &
-			EXYNOS_TMU_TEMP_MASK;
+	if (data->cal_type == TYPE_TWO_POINT_TRIMMING) {
+		data->temp_error2 = (trim_info >> tmu_85_shift) & tmu_temp_mask;
+		if (!data->temp_error2)
+			data->temp_error2 =
+				(data->efuse_value >> tmu_85_shift) &
+				tmu_temp_mask;
+	}
 }
 
 static int exynos_tmu_initialize(struct platform_device *pdev)
@@ -510,7 +514,6 @@ static void exynos5433_tmu_initialize(struct platform_device *pdev)
 	int sensor_id, cal_type;
 
 	trim_info = readl(data->base + EXYNOS_TMU_REG_TRIMINFO);
-	sanitize_temp_error(data, trim_info);
 
 	/* Read the temperature sensor id */
 	sensor_id = (trim_info & EXYNOS5433_TRIMINFO_SENSOR_ID_MASK)
@@ -532,6 +535,8 @@ static void exynos5433_tmu_initialize(struct platform_device *pdev)
 		break;
 	}
 
+	sanitize_temp_error(data, trim_info);
+
 	dev_info(&pdev->dev, "Calibration type is %d-point calibration\n",
 			cal_type ?  2 : 1);
 }
-- 
2.45.1