Re: [PATCH 3/3] coretemp: Get microcode revision from cpu_data v2

From: Jean Delvare
Date: Wed May 25 2011 - 16:55:39 EST


Hi Andi,

On Wed, 25 May 2011 12:32:28 -0700, Andi Kleen wrote:
> From: Andi Kleen <ak@xxxxxxxxxxxxxxx>
>
> Now that the ucode revision is available in cpu_data remove
> the existing code in coretemp.c to query it manually. Read the ucode
> revision from cpu_data instead

Where is this available? Not upstream yet, apparently. I get a build
failure here.

>
> v2: Fix misplaced variable init. Remove unused variables.
> Cc: jbeulich@xxxxxxxxxx
> Cc: fenghua.yu@xxxxxxxxx
> Cc: khali@xxxxxxxxxxxx
> Signed-off-by: Andi Kleen <ak@xxxxxxxxxxxxxxx>
> ---
> drivers/hwmon/coretemp.c | 31 +++++--------------------------
> 1 files changed, 5 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c
> index 9577c43..eec29d6 100644
> --- a/drivers/hwmon/coretemp.c
> +++ b/drivers/hwmon/coretemp.c
> @@ -324,15 +324,6 @@ static int get_tjmax(struct cpuinfo_x86 *c, u32 id, struct device *dev)
> }
> }
>
> -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 get_pkg_tjmax(unsigned int cpu, struct device *dev)
> {
> int err;
> @@ -425,29 +416,17 @@ static void update_ttarget(__u8 cpu_model, struct temp_data *tdata,
> static int chk_ucode_version(struct platform_device *pdev)
> {
> struct cpuinfo_x86 *c = &cpu_data(pdev->id);
> - int err;
> - u32 edx;
>
> /*
> * 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 */
> - err = smp_call_function_single(pdev->id, get_ucode_rev_on_cpu,
> - &edx, 1);

As a side note, this is fixing a section mismatch, as
get_ucode_rev_on_cpu() was declared __devinit but chk_ucode_version()
isn't. Thankfully this doesn't affect previous kernels. As far as I can
see, chk_ucode_version could be made __devinit. I'll send a patch.

> - if (err) {
> - dev_err(&pdev->dev,
> - "Cannot determine microcode revision of "
> - "CPU#%u (%d)!\n", pdev->id, err);
> - return -ENODEV;
> - } else if (edx < 0x39) {
> - dev_err(&pdev->dev,
> - "Errata AE18 not fixed, update BIOS or "
> - "microcode of the CPU!\n");
> - return -ENODEV;
> - }
> + if (c->x86_model == 0xe && c->x86_mask < 0xc && c->cpu_update < 0x39) {
> + dev_err(&pdev->dev,
> + "Errata AE18 not fixed, update BIOS or "
> + "microcode of the CPU!\n");
> + return -ENODEV;
> }
> return 0;
> }

This all looks reasonable, but I am not able to test it.

--
Jean Delvare
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