From 3247800676c4a04352cde72b9935b57ffc72ce15 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Fri, 8 Oct 2010 04:59:38 -0400 Subject: hwmon: (coretemp) fix reading of microcode revision (v2) According to the documentation, simply reading the respective MSR isn't sufficient: It should be written with zeros, cpuid(1) be executed, and then read (see arch/x86/kernel/cpu/intel.c for an example). v2: Fail probe when microcode revision cannot be determined, but is needed to check for proper operation. Signed-off-by: Jan Beulich Cc: Fenghua Yu Cc: Chen Gong Cc: Jean Delvare Acked-by: Fenghua Yu Signed-off-by: Guenter Roeck --- drivers/hwmon/coretemp.c | 20 ++++++++++++++++++-- 1 file changed, 18 insertions(+), 2 deletions(-) (limited to 'drivers/hwmon') diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c index 467488c278e..42de98d73ff 100644 --- a/drivers/hwmon/coretemp.c +++ b/drivers/hwmon/coretemp.c @@ -289,6 +289,15 @@ static int __devinit get_tjmax(struct cpuinfo_x86 *c, u32 id, } } +static void __devinit get_ucode_rev_on_cpu(void *edx) +{ + u32 eax; + + wrmsr(MSR_IA32_UCODE_REV, 0, 0); + sync_core(); + rdmsr(MSR_IA32_UCODE_REV, eax, *(u32 *)edx); +} + static int __devinit coretemp_probe(struct platform_device *pdev) { struct coretemp_data *data; @@ -324,8 +333,15 @@ static int __devinit coretemp_probe(struct platform_device *pdev) 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) { + err = smp_call_function_single(data->id, get_ucode_rev_on_cpu, + &edx, 1); + if (err) { + dev_err(&pdev->dev, + "Cannot determine microcode revision of " + "CPU#%u (%d)!\n", data->id, err); + err = -ENODEV; + goto exit_free; + } else if (edx < 0x39) { err = -ENODEV; dev_err(&pdev->dev, "Errata AE18 not fixed, update BIOS or " -- cgit v1.2.3-70-g09d2