diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
index 45e3e17..7efaeaa 100644
--- a/drivers/acpi/battery.c
+++ b/drivers/acpi/battery.c
@@ -34,6 +34,7 @@
 #include <linux/dmi.h>
 #include <linux/slab.h>
 #include <linux/suspend.h>
+#include <asm/unaligned.h>
 
 #ifdef CONFIG_ACPI_PROCFS_POWER
 #include <linux/proc_fs.h>
@@ -95,6 +96,18 @@
 	ACPI_BATTERY_ALARM_PRESENT,
 	ACPI_BATTERY_XINFO_PRESENT,
 	ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY,
+	/* On Lenovo Thinkpad models from 2010 and 2011, the power unit
+	   switches between mWh and mAh depending on whether the system
+	   is running on battery or not.  When mAh is the unit, most
+	   reported values are incorrect and need to be adjusted by
+	   10000/design_voltage.  Verified on x201, t410, t410s, and x220.
+	   Pre-2010 and 2012 models appear to always report in mWh and
+	   are thus unaffected (tested with t42, t61, t500, x200, x300,
+	   and x230).  Also, in mid-2012 Lenovo issued a BIOS update for
+	   the 2011 models that fixes the issue (tested on x220 with a
+	   post-1.29 BIOS), but as of Nov. 2012, no such update is
+	   available for the 2010 models.  */
+	ACPI_BATTERY_QUIRK_THINKPAD_MAH,
 };
 
 struct acpi_battery {
@@ -438,6 +451,21 @@
 	kfree(buffer.pointer);
 	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
 		battery->full_charge_capacity = battery->design_capacity;
+	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
+	    battery->power_unit && battery->design_voltage) {
+		battery->design_capacity = battery->design_capacity *
+		    10000 / battery->design_voltage;
+		battery->full_charge_capacity = battery->full_charge_capacity *
+		    10000 / battery->design_voltage;
+		battery->design_capacity_warning =
+		    battery->design_capacity_warning *
+		    10000 / battery->design_voltage;
+		/* Curiously, design_capacity_low, unlike the rest of them,
+		   is correct.  */
+		/* capacity_granularity_* equal 1 on the systems tested, so
+		   it's impossible to tell if they would need an adjustment
+		   or not if their values were higher.  */
+	}
 	return result;
 }
 
@@ -486,6 +514,11 @@
 	    && battery->capacity_now >= 0 && battery->capacity_now <= 100)
 		battery->capacity_now = (battery->capacity_now *
 				battery->full_charge_capacity) / 100;
+	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
+	    battery->power_unit && battery->design_voltage) {
+		battery->capacity_now = battery->capacity_now *
+		    10000 / battery->design_voltage;
+	}
 	return result;
 }
 
@@ -595,6 +628,24 @@
 	mutex_unlock(&battery->sysfs_lock);
 }
 
+static void find_battery(const struct dmi_header *dm, void *private)
+{
+	struct acpi_battery *battery = (struct acpi_battery *)private;
+	/* Note: the hardcoded offsets below have been extracted from
+	   the source code of dmidecode.  */
+	if (dm->type == DMI_ENTRY_PORTABLE_BATTERY && dm->length >= 8) {
+		const u8 *dmi_data = (const u8 *)(dm + 1);
+		int dmi_capacity = get_unaligned((const u16 *)(dmi_data + 6));
+		if (dm->length >= 18)
+			dmi_capacity *= dmi_data[17];
+		if (battery->design_capacity * battery->design_voltage / 1000
+		    != dmi_capacity &&
+		    battery->design_capacity * 10 == dmi_capacity)
+			set_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
+				&battery->flags);
+	}
+}
+
 /*
  * According to the ACPI spec, some kinds of primary batteries can
  * report percentage battery remaining capacity directly to OS.
@@ -620,6 +671,32 @@
 		battery->capacity_now = (battery->capacity_now *
 				battery->full_charge_capacity) / 100;
 	}
+
+	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags))
+		return ;
+
+	if (battery->power_unit && dmi_name_in_vendors("LENOVO")) {
+		const char *s;
+		s = dmi_get_system_info(DMI_PRODUCT_VERSION);
+		if (s && !strnicmp(s, "ThinkPad", 8)) {
+			dmi_walk(find_battery, battery);
+			if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
+				     &battery->flags) &&
+			    battery->design_voltage) {
+				battery->design_capacity =
+				    battery->design_capacity *
+				    10000 / battery->design_voltage;
+				battery->full_charge_capacity =
+				    battery->full_charge_capacity *
+				    10000 / battery->design_voltage;
+				battery->design_capacity_warning =
+				    battery->design_capacity_warning *
+				    10000 / battery->design_voltage;
+				battery->capacity_now = battery->capacity_now *
+				    10000 / battery->design_voltage;
+			}
+		}
+	}
 }
 
 static int acpi_battery_update(struct acpi_battery *battery)