Commit 67f363b1 authored by Rudolf Marek's avatar Rudolf Marek Committed by Jean Delvare
Browse files

hwmon/coretemp: Add more safety checks 



Add detection of AE18 Errata of Core processor and warns
users that the absolute readings might be wrong for Core2 processor.

Signed-off-by: default avatarRudolf Marek <r.marek@assembler.cz>
Signed-off-by: default avatarJean Delvare <khali@linux-fr.org>
parent 7574d7e9

drivers/hwmon/coretemp.c

+29 −3
Original line number Diff line number Diff line
@@ -176,6 +176,22 @@ static int __devinit coretemp_probe(struct platform_device *pdev) 
		goto exit_free;

	}



	/* Check if we have problem with errata AE18 of Core processors:

	   Readings might stop update when processor visited too deep sleep,

	   fixed for stepping D0 (6EC).

	*/



	if ((c->x86_model == 0xe) && (c->x86_mask < 0xc)) {

		/* check for microcode update */

		rdmsr_on_cpu(data->id, MSR_IA32_UCODE_REV, &eax, &edx);

		if (edx < 0x39) {

			dev_err(&pdev->dev,

				"Errata AE18 not fixed, update BIOS or "

				"microcode of the CPU!\n");

			goto exit_free;

		}

	}



	/* Some processors have Tjmax 85 following magic should detect it

	   Intel won't disclose the information without signed NDA, but

	   individuals cannot sign it. Catch(ed) 22.
@@ -193,6 +209,19 @@ static int __devinit coretemp_probe(struct platform_device *pdev) 
		}

	}



	/* Intel says that above should not work for desktop Core2 processors,

	   but it seems to work. There is no other way how get the absolute

	   readings. Warn the user about this. First check if are desktop,

	   bit 50 of MSR_IA32_PLATFORM_ID should be 0.

	*/



	rdmsr_safe_on_cpu(data->id, MSR_IA32_PLATFORM_ID, &eax, &edx);



	if ((c->x86_model == 0xf) && (!(edx & 0x00040000))) {

		dev_warn(&pdev->dev, "Using undocumented features, absolute "

			 "temperature might be wrong!\n");

	}



	platform_set_drvdata(pdev, data);



	if ((err = sysfs_create_group(&pdev->dev.kobj, &coretemp_group)))
@@ -330,9 +359,6 @@ static int __init coretemp_init(void) 
	int i, err = -ENODEV;

	struct pdev_entry *p, *n;



	printk(KERN_NOTICE DRVNAME ": This driver uses undocumented features "

		"of Core CPU. Temperature might be wrong!\n");



	/* quick check if we run Intel */

	if (cpu_data[0].x86_vendor != X86_VENDOR_INTEL)

		goto exit;