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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org, Mark Pearson <markpearson@lenovo.com>,
	Hans de Goede <hdegoede@redhat.com>
Subject: [PATCH 5.12 16/17] platform/x86: thinkpad_acpi: Correct thermal sensor allocation
Date: Wed,  5 May 2021 14:06:11 +0200	[thread overview]
Message-ID: <20210505112325.479732835@linuxfoundation.org> (raw)
In-Reply-To: <20210505112324.956720416@linuxfoundation.org>

From: Mark Pearson <markpearson@lenovo.com>

commit 6759e18e5cd8745a5dfc5726e4a3db5281ec1639 upstream.

On recent Thinkpad platforms it was reported that temp sensor 11 was
always incorrectly displaying 66C. It turns out the reason for this is
that this location in EC RAM is not a temperature sensor but is the
power supply ID (offset 0xC2).

Based on feedback from the Lenovo firmware team the EC RAM version can
be determined and for the current version (3) only the 0x78 to 0x7F
range is used for temp sensors. I don't have any details for earlier
versions so I have left the implementation unaltered there.

Note - in this block only 0x78 and 0x79 are officially designated (CPU &
GPU sensors). The use of the other locations in the block will vary from
platform to platform; but the existing logic to detect a sensor presence
holds.

Signed-off-by: Mark Pearson <markpearson@lenovo.com>
Link: https://lore.kernel.org/r/20210407212015.298222-1-markpearson@lenovo.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/platform/x86/thinkpad_acpi.c |   31 ++++++++++++++++++++++---------
 1 file changed, 22 insertions(+), 9 deletions(-)

--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -6260,6 +6260,7 @@ enum thermal_access_mode {
 enum { /* TPACPI_THERMAL_TPEC_* */
 	TP_EC_THERMAL_TMP0 = 0x78,	/* ACPI EC regs TMP 0..7 */
 	TP_EC_THERMAL_TMP8 = 0xC0,	/* ACPI EC regs TMP 8..15 */
+	TP_EC_FUNCREV      = 0xEF,      /* ACPI EC Functional revision */
 	TP_EC_THERMAL_TMP_NA = -128,	/* ACPI EC sensor not available */
 
 	TPACPI_THERMAL_SENSOR_NA = -128000, /* Sensor not available */
@@ -6458,7 +6459,7 @@ static const struct attribute_group ther
 
 static int __init thermal_init(struct ibm_init_struct *iibm)
 {
-	u8 t, ta1, ta2;
+	u8 t, ta1, ta2, ver = 0;
 	int i;
 	int acpi_tmp7;
 	int res;
@@ -6473,7 +6474,14 @@ static int __init thermal_init(struct ib
 		 * 0x78-0x7F, 0xC0-0xC7.  Registers return 0x00 for
 		 * non-implemented, thermal sensors return 0x80 when
 		 * not available
+		 * The above rule is unfortunately flawed. This has been seen with
+		 * 0xC2 (power supply ID) causing thermal control problems.
+		 * The EC version can be determined by offset 0xEF and at least for
+		 * version 3 the Lenovo firmware team confirmed that registers 0xC0-0xC7
+		 * are not thermal registers.
 		 */
+		if (!acpi_ec_read(TP_EC_FUNCREV, &ver))
+			pr_warn("Thinkpad ACPI EC unable to access EC version\n");
 
 		ta1 = ta2 = 0;
 		for (i = 0; i < 8; i++) {
@@ -6483,11 +6491,13 @@ static int __init thermal_init(struct ib
 				ta1 = 0;
 				break;
 			}
-			if (acpi_ec_read(TP_EC_THERMAL_TMP8 + i, &t)) {
-				ta2 |= t;
-			} else {
-				ta1 = 0;
-				break;
+			if (ver < 3) {
+				if (acpi_ec_read(TP_EC_THERMAL_TMP8 + i, &t)) {
+					ta2 |= t;
+				} else {
+					ta1 = 0;
+					break;
+				}
 			}
 		}
 		if (ta1 == 0) {
@@ -6500,9 +6510,12 @@ static int __init thermal_init(struct ib
 				thermal_read_mode = TPACPI_THERMAL_NONE;
 			}
 		} else {
-			thermal_read_mode =
-			    (ta2 != 0) ?
-			    TPACPI_THERMAL_TPEC_16 : TPACPI_THERMAL_TPEC_8;
+			if (ver >= 3)
+				thermal_read_mode = TPACPI_THERMAL_TPEC_8;
+			else
+				thermal_read_mode =
+					(ta2 != 0) ?
+					TPACPI_THERMAL_TPEC_16 : TPACPI_THERMAL_TPEC_8;
 		}
 	} else if (acpi_tmp7) {
 		if (tpacpi_is_ibm() &&



  parent reply	other threads:[~2021-05-05 12:12 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-05-05 12:05 [PATCH 5.12 00/17] 5.12.2-rc1 review Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.12 01/17] mips: Do not include hi and lo in clobber list for R6 Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.12 02/17] netfilter: conntrack: Make global sysctls readonly in non-init netns Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.12 03/17] net: usb: ax88179_178a: initialize local variables before use Greg Kroah-Hartman
2021-05-05 12:05 ` [PATCH 5.12 04/17] drm/i915: Disable runtime power management during shutdown Greg Kroah-Hartman
2021-05-05 12:06 ` [PATCH 5.12 05/17] bpf: Fix masking negation logic upon negative dst register Greg Kroah-Hartman
2021-05-05 12:06 ` [PATCH 5.12 06/17] bpf: Fix leakage of uninitialized bpf stack under speculation Greg Kroah-Hartman
2021-05-05 12:06 ` [PATCH 5.12 07/17] net: qrtr: Avoid potential use after free in MHI send Greg Kroah-Hartman
2021-05-05 12:06 ` [PATCH 5.12 08/17] ovl: fix leaked dentry Greg Kroah-Hartman
2021-05-05 12:06 ` [PATCH 5.12 09/17] ovl: allow upperdir inside lowerdir Greg Kroah-Hartman
2021-05-05 12:06 ` [PATCH 5.12 10/17] ALSA: usb-audio: Add MIDI quirk for Vox ToneLab EX Greg Kroah-Hartman
2021-05-05 12:06 ` [PATCH 5.12 11/17] ALSA: usb-audio: Fix implicit sync clearance at stopping stream Greg Kroah-Hartman
2021-05-05 12:06 ` [PATCH 5.12 12/17] USB: Add LPM quirk for Lenovo ThinkPad USB-C Dock Gen2 Ethernet Greg Kroah-Hartman
2021-05-05 12:06 ` [PATCH 5.12 13/17] USB: Add reset-resume quirk for WD19s Realtek Hub Greg Kroah-Hartman
2021-05-05 12:06 ` [PATCH 5.12 14/17] ASoC: ak4458: Add MODULE_DEVICE_TABLE Greg Kroah-Hartman
2021-05-05 12:06 ` [PATCH 5.12 15/17] ASoC: ak5558: " Greg Kroah-Hartman
2021-05-05 12:06 ` Greg Kroah-Hartman [this message]
2021-05-05 12:06 ` [PATCH 5.12 17/17] perf/core: Fix unconditional security_locked_down() call Greg Kroah-Hartman
2021-05-05 17:52 ` [PATCH 5.12 00/17] 5.12.2-rc1 review Fox Chen
2021-05-05 19:09 ` Naresh Kamboju
2021-05-05 19:44 ` Florian Fainelli
2021-05-06  1:59 ` Guenter Roeck

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