[1/2] platform/x86: thinkpad_acpi: Simplify thermal mode checking

Message ID 20240214052959.8550-1-vishnuocv@gmail.com
State New
Headers
Series [1/2] platform/x86: thinkpad_acpi: Simplify thermal mode checking |

Commit Message

Vishnu Sankar Feb. 14, 2024, 5:29 a.m. UTC
  Add a thermal_read_mode_check helper function to make the code
simpler during init.
This helps particularly when the new TPEC_12 mode is added in
the next patch.

Suggested-by: Ilpo Jarvinen <ilpo.jarvinen@intel.com>
Signed-off-by: Vishnu Sankar <vishnuocv@gmail.com>
---
 drivers/platform/x86/thinkpad_acpi.c | 136 +++++++++++++--------------
 1 file changed, 66 insertions(+), 70 deletions(-)
  

Comments

Ilpo Järvinen Feb. 14, 2024, 9:52 a.m. UTC | #1
On Wed, 14 Feb 2024, Vishnu Sankar wrote:

Thanks for doing this, it's major improvement to readability already as 
is, and even more of after the second patch!!

> Add a thermal_read_mode_check helper function to make the code

thermal_read_mode_check()

remove "function" as it's obvious.

> simpler during init.
> This helps particularly when the new TPEC_12 mode is added in
> the next patch.

Flow the paragraph normally without the premature line break.
 
> Suggested-by: Ilpo Jarvinen <ilpo.jarvinen@intel.com>

This is not my email address, please use

Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

> Signed-off-by: Vishnu Sankar <vishnuocv@gmail.com>
> ---
>  drivers/platform/x86/thinkpad_acpi.c | 136 +++++++++++++--------------
>  1 file changed, 66 insertions(+), 70 deletions(-)
> 
> diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
> index c4895e9bc714..2428c8bd0fa2 100644
> --- a/drivers/platform/x86/thinkpad_acpi.c
> +++ b/drivers/platform/x86/thinkpad_acpi.c
> @@ -6147,6 +6147,71 @@ struct ibm_thermal_sensors_struct {
>  static enum thermal_access_mode thermal_read_mode;
>  static bool thermal_use_labels;
>  
> +/* Function to check thermal read mode */
> +static enum thermal_access_mode thermal_read_mode_check(void)
> +{
> +	u8 t, ta1, ta2, ver = 0;
> +	int i;
> +
> +	if (thinkpad_id.ec_model) {
> +		/*
> +		 * Direct EC access mode: sensors at registers
> +		 * 0x78-0x7F, 0xC0-0xC7.  Registers return 0x00 for

Remove the double space, one is enough in kernel comments.

> +		 * non-implemented, thermal sensors return 0x80 when
> +		 * not available

Add the missing . please.

Perhaps add a empty line here to make this two paragraphs.

> +		 * 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.
> +		 */

While the patch touches this, this entire comment should be reflowed 
properly for 80 columns.

> +		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++) {
> +			if (acpi_ec_read(TP_EC_THERMAL_TMP0 + i, &t)) {
> +				ta1 |= 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) {
> +			pr_err("ThinkPad ACPI EC access misbehaving, disabling thermal sensors access\n");
> +			return TPACPI_THERMAL_NONE;
> +		}
> +
> +		if (ver >= 3) {
> +			thermal_use_labels = true;
> +			return TPACPI_THERMAL_TPEC_8;
> +		}
> +
> +		return (ta2 != 0) ? TPACPI_THERMAL_TPEC_16 : TPACPI_THERMAL_TPEC_8;
> +	}
> +
> +	if (acpi_evalf(ec_handle, NULL, "TMP7", "qv")) {
> +		if (tpacpi_is_ibm() &&
> +		    acpi_evalf(ec_handle, NULL, "UPDT", "qv"))

Single line and keep the braces please (I know it will go >80 chars but no 
important info is lost).

> +			/* 600e/x, 770e, 770x */
> +			return TPACPI_THERMAL_ACPI_UPDT;
> +		/* IBM/LENOVO DSDT EC.TMPx access, max 8 sensors */
> +		return TPACPI_THERMAL_ACPI_TMP07;
> +	}
> +
> +	/* temperatures not supported on 570, G4x, R30, R31, R32 */
> +	return TPACPI_THERMAL_NONE;
> +}
> +
>  /* idx is zero-based */
>  static int thermal_get_sensor(int idx, s32 *value)
>  {
> @@ -6375,78 +6440,9 @@ static const struct attribute_group temp_label_attr_group = {
>  
>  static int __init thermal_init(struct ibm_init_struct *iibm)
>  {
> -	u8 t, ta1, ta2, ver = 0;
> -	int i;
> -	int acpi_tmp7;
> -
>  	vdbg_printk(TPACPI_DBG_INIT, "initializing thermal subdriver\n");
>  
> -	acpi_tmp7 = acpi_evalf(ec_handle, NULL, "TMP7", "qv");
> -
> -	if (thinkpad_id.ec_model) {
> -		/*
> -		 * Direct EC access mode: sensors at registers
> -		 * 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++) {
> -			if (acpi_ec_read(TP_EC_THERMAL_TMP0 + i, &t)) {
> -				ta1 |= 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) {
> -			/* This is sheer paranoia, but we handle it anyway */
> -			if (acpi_tmp7) {
> -				pr_err("ThinkPad ACPI EC access misbehaving, falling back to ACPI TMPx access mode\n");
> -				thermal_read_mode = TPACPI_THERMAL_ACPI_TMP07;

Eh, where did this go in the new helper?
  
Ilpo Järvinen Feb. 14, 2024, 10:16 a.m. UTC | #2
On Wed, 14 Feb 2024, Vishnu Sankar wrote:

Thanks for doing this, it's major improvement to readability already as
is, and even more of after the second patch!!

> Add a thermal_read_mode_check helper function to make the code

thermal_read_mode_check()

remove "function" as it's obvious.

> simpler during init.
> This helps particularly when the new TPEC_12 mode is added in
> the next patch.

Flow the paragraph normally without the premature line break.

> Suggested-by: Ilpo Jarvinen <ilpo.jarvinen@intel.com>

This is not my email address, please use

Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

> Signed-off-by: Vishnu Sankar <vishnuocv@gmail.com>
> ---
>  drivers/platform/x86/thinkpad_acpi.c | 136 +++++++++++++--------------
>  1 file changed, 66 insertions(+), 70 deletions(-)
> 
> diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
> index c4895e9bc714..2428c8bd0fa2 100644
> --- a/drivers/platform/x86/thinkpad_acpi.c
> +++ b/drivers/platform/x86/thinkpad_acpi.c
> @@ -6147,6 +6147,71 @@ struct ibm_thermal_sensors_struct {
>  static enum thermal_access_mode thermal_read_mode;
>  static bool thermal_use_labels;
>  
> +/* Function to check thermal read mode */
> +static enum thermal_access_mode thermal_read_mode_check(void)
> +{
> +	u8 t, ta1, ta2, ver = 0;
> +	int i;
> +
> +	if (thinkpad_id.ec_model) {
> +		/*
> +		 * Direct EC access mode: sensors at registers
> +		 * 0x78-0x7F, 0xC0-0xC7.  Registers return 0x00 for

While this comment is touches, lets make minor improvements to it.

Remove the double space, they are not needed in kernel comments.

> +		 * non-implemented, thermal sensors return 0x80 when
> +		 * not available

Please add the missing .

Perhaps add an empty line here to break the comment into two paragraphs?

> +		 * 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.

Please reflow the entire comment to 80 chars.

> +		 */
> +		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++) {
> +			if (acpi_ec_read(TP_EC_THERMAL_TMP0 + i, &t)) {
> +				ta1 |= 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) {
> +			pr_err("ThinkPad ACPI EC access misbehaving, disabling thermal sensors access\n");
> +			return TPACPI_THERMAL_NONE;
> +		}
> +
> +		if (ver >= 3) {
> +			thermal_use_labels = true;
> +			return TPACPI_THERMAL_TPEC_8;
> +		}
> +
> +		return (ta2 != 0) ? TPACPI_THERMAL_TPEC_16 : TPACPI_THERMAL_TPEC_8;
> +	}
> +
> +	if (acpi_evalf(ec_handle, NULL, "TMP7", "qv")) {
> +		if (tpacpi_is_ibm() &&
> +		    acpi_evalf(ec_handle, NULL, "UPDT", "qv"))

Put this to single line and retain the braces please (I know it will be 
>80 char but nothing important is lost).

> +			/* 600e/x, 770e, 770x */
> +			return TPACPI_THERMAL_ACPI_UPDT;
> +		/* IBM/LENOVO DSDT EC.TMPx access, max 8 sensors */
> +		return TPACPI_THERMAL_ACPI_TMP07;
> +	}
> +
> +	/* temperatures not supported on 570, G4x, R30, R31, R32 */
> +	return TPACPI_THERMAL_NONE;
> +}
> +
>  /* idx is zero-based */
>  static int thermal_get_sensor(int idx, s32 *value)
>  {
> @@ -6375,78 +6440,9 @@ static const struct attribute_group temp_label_attr_group = {
>  
>  static int __init thermal_init(struct ibm_init_struct *iibm)
>  {
> -	u8 t, ta1, ta2, ver = 0;
> -	int i;
> -	int acpi_tmp7;
> -
>  	vdbg_printk(TPACPI_DBG_INIT, "initializing thermal subdriver\n");
>  
> -	acpi_tmp7 = acpi_evalf(ec_handle, NULL, "TMP7", "qv");
> -
> -	if (thinkpad_id.ec_model) {
> -		/*
> -		 * Direct EC access mode: sensors at registers
> -		 * 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++) {
> -			if (acpi_ec_read(TP_EC_THERMAL_TMP0 + i, &t)) {
> -				ta1 |= 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) {
> -			/* This is sheer paranoia, but we handle it anyway */
> -			if (acpi_tmp7) {
> -				pr_err("ThinkPad ACPI EC access misbehaving, falling back to ACPI TMPx access mode\n");
> -				thermal_read_mode = TPACPI_THERMAL_ACPI_TMP07;

Eh, where did this go in the new helper?
  
Vishnu Sankar Feb. 14, 2024, 11:18 p.m. UTC | #3
Ilpo,
Thanks a lot for the review.

On Wed, Feb 14, 2024 at 7:14 PM Ilpo Järvinen
<ilpo.jarvinen@linux.intel.com> wrote:
>
> On Wed, 14 Feb 2024, Vishnu Sankar wrote:
>
> Thanks for doing this, it's major improvement to readability already as
> is, and even more of after the second patch!!
>
> > Add a thermal_read_mode_check helper function to make the code
>
> thermal_read_mode_check()
>
> remove "function" as it's obvious.
Acked
>
> > simpler during init.
> > This helps particularly when the new TPEC_12 mode is added in
> > the next patch.
>
> Flow the paragraph normally without the premature line break.
Acked.
>
> > Suggested-by: Ilpo Jarvinen <ilpo.jarvinen@intel.com>
>
> This is not my email address, please use
>
> Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Sorry for this.
Will correct email address.
>
> > Signed-off-by: Vishnu Sankar <vishnuocv@gmail.com>
> > ---
> >  drivers/platform/x86/thinkpad_acpi.c | 136 +++++++++++++--------------
> >  1 file changed, 66 insertions(+), 70 deletions(-)
> >
> > diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
> > index c4895e9bc714..2428c8bd0fa2 100644
> > --- a/drivers/platform/x86/thinkpad_acpi.c
> > +++ b/drivers/platform/x86/thinkpad_acpi.c
> > @@ -6147,6 +6147,71 @@ struct ibm_thermal_sensors_struct {
> >  static enum thermal_access_mode thermal_read_mode;
> >  static bool thermal_use_labels;
> >
> > +/* Function to check thermal read mode */
> > +static enum thermal_access_mode thermal_read_mode_check(void)
> > +{
> > +     u8 t, ta1, ta2, ver = 0;
> > +     int i;
> > +
> > +     if (thinkpad_id.ec_model) {
> > +             /*
> > +              * Direct EC access mode: sensors at registers
> > +              * 0x78-0x7F, 0xC0-0xC7.  Registers return 0x00 for
>
> Remove the double space, one is enough in kernel comments.
Acked
>
> > +              * non-implemented, thermal sensors return 0x80 when
> > +              * not available
>
> Add the missing . please.
>
> Perhaps add a empty line here to make this two paragraphs.
Acked
>
> > +              * 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.
> > +              */
>
> While the patch touches this, this entire comment should be reflowed
> properly for 80 columns.
Will try re-writing the comments block for 80 columns.
>
> > +             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++) {
> > +                     if (acpi_ec_read(TP_EC_THERMAL_TMP0 + i, &t)) {
> > +                             ta1 |= 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) {
> > +                     pr_err("ThinkPad ACPI EC access misbehaving, disabling thermal sensors access\n");
> > +                     return TPACPI_THERMAL_NONE;
> > +             }
> > +
> > +             if (ver >= 3) {
> > +                     thermal_use_labels = true;
> > +                     return TPACPI_THERMAL_TPEC_8;
> > +             }
> > +
> > +             return (ta2 != 0) ? TPACPI_THERMAL_TPEC_16 : TPACPI_THERMAL_TPEC_8;
> > +     }
> > +
> > +     if (acpi_evalf(ec_handle, NULL, "TMP7", "qv")) {
> > +             if (tpacpi_is_ibm() &&
> > +                 acpi_evalf(ec_handle, NULL, "UPDT", "qv"))
>
> Single line and keep the braces please (I know it will go >80 chars but no
> important info is lost).
Acked.
Will change this.
>
> > +                     /* 600e/x, 770e, 770x */
> > +                     return TPACPI_THERMAL_ACPI_UPDT;
> > +             /* IBM/LENOVO DSDT EC.TMPx access, max 8 sensors */
> > +             return TPACPI_THERMAL_ACPI_TMP07;
> > +     }
> > +
> > +     /* temperatures not supported on 570, G4x, R30, R31, R32 */
> > +     return TPACPI_THERMAL_NONE;
> > +}
> > +
> >  /* idx is zero-based */
> >  static int thermal_get_sensor(int idx, s32 *value)
> >  {
> > @@ -6375,78 +6440,9 @@ static const struct attribute_group temp_label_attr_group = {
> >
> >  static int __init thermal_init(struct ibm_init_struct *iibm)
> >  {
> > -     u8 t, ta1, ta2, ver = 0;
> > -     int i;
> > -     int acpi_tmp7;
> > -
> >       vdbg_printk(TPACPI_DBG_INIT, "initializing thermal subdriver\n");
> >
> > -     acpi_tmp7 = acpi_evalf(ec_handle, NULL, "TMP7", "qv");
> > -
> > -     if (thinkpad_id.ec_model) {
> > -             /*
> > -              * Direct EC access mode: sensors at registers
> > -              * 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++) {
> > -                     if (acpi_ec_read(TP_EC_THERMAL_TMP0 + i, &t)) {
> > -                             ta1 |= 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) {
> > -                     /* This is sheer paranoia, but we handle it anyway */
> > -                     if (acpi_tmp7) {
> > -                             pr_err("ThinkPad ACPI EC access misbehaving, falling back to ACPI TMPx access mode\n");
> > -                             thermal_read_mode = TPACPI_THERMAL_ACPI_TMP07;
>
> Eh, where did this go in the new helper?
Sorry.
This will be added in V2.
>
> --
>  i.
>
> > -                     } else {
> > -                             pr_err("ThinkPad ACPI EC access misbehaving, disabling thermal sensors access\n");
> > -                             thermal_read_mode = TPACPI_THERMAL_NONE;
> > -                     }
> > -             } else {
> > -                     if (ver >= 3) {
> > -                             thermal_read_mode = TPACPI_THERMAL_TPEC_8;
> > -                             thermal_use_labels = true;
> > -                     } else {
> > -                             thermal_read_mode =
> > -                                     (ta2 != 0) ?
> > -                                     TPACPI_THERMAL_TPEC_16 : TPACPI_THERMAL_TPEC_8;
> > -                     }
> > -             }
> > -     } else if (acpi_tmp7) {
> > -             if (tpacpi_is_ibm() &&
> > -                 acpi_evalf(ec_handle, NULL, "UPDT", "qv")) {
> > -                     /* 600e/x, 770e, 770x */
> > -                     thermal_read_mode = TPACPI_THERMAL_ACPI_UPDT;
> > -             } else {
> > -                     /* IBM/LENOVO DSDT EC.TMPx access, max 8 sensors */
> > -                     thermal_read_mode = TPACPI_THERMAL_ACPI_TMP07;
> > -             }
> > -     } else {
> > -             /* temperatures not supported on 570, G4x, R30, R31, R32 */
> > -             thermal_read_mode = TPACPI_THERMAL_NONE;
> > -     }
> > +     thermal_read_mode = thermal_read_mode_check();
> >
> >       vdbg_printk(TPACPI_DBG_INIT, "thermal is %s, mode %d\n",
> >               str_supported(thermal_read_mode != TPACPI_THERMAL_NONE),
> >
  

Patch

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
index c4895e9bc714..2428c8bd0fa2 100644
--- a/drivers/platform/x86/thinkpad_acpi.c
+++ b/drivers/platform/x86/thinkpad_acpi.c
@@ -6147,6 +6147,71 @@  struct ibm_thermal_sensors_struct {
 static enum thermal_access_mode thermal_read_mode;
 static bool thermal_use_labels;
 
+/* Function to check thermal read mode */
+static enum thermal_access_mode thermal_read_mode_check(void)
+{
+	u8 t, ta1, ta2, ver = 0;
+	int i;
+
+	if (thinkpad_id.ec_model) {
+		/*
+		 * Direct EC access mode: sensors at registers
+		 * 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++) {
+			if (acpi_ec_read(TP_EC_THERMAL_TMP0 + i, &t)) {
+				ta1 |= 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) {
+			pr_err("ThinkPad ACPI EC access misbehaving, disabling thermal sensors access\n");
+			return TPACPI_THERMAL_NONE;
+		}
+
+		if (ver >= 3) {
+			thermal_use_labels = true;
+			return TPACPI_THERMAL_TPEC_8;
+		}
+
+		return (ta2 != 0) ? TPACPI_THERMAL_TPEC_16 : TPACPI_THERMAL_TPEC_8;
+	}
+
+	if (acpi_evalf(ec_handle, NULL, "TMP7", "qv")) {
+		if (tpacpi_is_ibm() &&
+		    acpi_evalf(ec_handle, NULL, "UPDT", "qv"))
+			/* 600e/x, 770e, 770x */
+			return TPACPI_THERMAL_ACPI_UPDT;
+		/* IBM/LENOVO DSDT EC.TMPx access, max 8 sensors */
+		return TPACPI_THERMAL_ACPI_TMP07;
+	}
+
+	/* temperatures not supported on 570, G4x, R30, R31, R32 */
+	return TPACPI_THERMAL_NONE;
+}
+
 /* idx is zero-based */
 static int thermal_get_sensor(int idx, s32 *value)
 {
@@ -6375,78 +6440,9 @@  static const struct attribute_group temp_label_attr_group = {
 
 static int __init thermal_init(struct ibm_init_struct *iibm)
 {
-	u8 t, ta1, ta2, ver = 0;
-	int i;
-	int acpi_tmp7;
-
 	vdbg_printk(TPACPI_DBG_INIT, "initializing thermal subdriver\n");
 
-	acpi_tmp7 = acpi_evalf(ec_handle, NULL, "TMP7", "qv");
-
-	if (thinkpad_id.ec_model) {
-		/*
-		 * Direct EC access mode: sensors at registers
-		 * 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++) {
-			if (acpi_ec_read(TP_EC_THERMAL_TMP0 + i, &t)) {
-				ta1 |= 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) {
-			/* This is sheer paranoia, but we handle it anyway */
-			if (acpi_tmp7) {
-				pr_err("ThinkPad ACPI EC access misbehaving, falling back to ACPI TMPx access mode\n");
-				thermal_read_mode = TPACPI_THERMAL_ACPI_TMP07;
-			} else {
-				pr_err("ThinkPad ACPI EC access misbehaving, disabling thermal sensors access\n");
-				thermal_read_mode = TPACPI_THERMAL_NONE;
-			}
-		} else {
-			if (ver >= 3) {
-				thermal_read_mode = TPACPI_THERMAL_TPEC_8;
-				thermal_use_labels = true;
-			} else {
-				thermal_read_mode =
-					(ta2 != 0) ?
-					TPACPI_THERMAL_TPEC_16 : TPACPI_THERMAL_TPEC_8;
-			}
-		}
-	} else if (acpi_tmp7) {
-		if (tpacpi_is_ibm() &&
-		    acpi_evalf(ec_handle, NULL, "UPDT", "qv")) {
-			/* 600e/x, 770e, 770x */
-			thermal_read_mode = TPACPI_THERMAL_ACPI_UPDT;
-		} else {
-			/* IBM/LENOVO DSDT EC.TMPx access, max 8 sensors */
-			thermal_read_mode = TPACPI_THERMAL_ACPI_TMP07;
-		}
-	} else {
-		/* temperatures not supported on 570, G4x, R30, R31, R32 */
-		thermal_read_mode = TPACPI_THERMAL_NONE;
-	}
+	thermal_read_mode = thermal_read_mode_check();
 
 	vdbg_printk(TPACPI_DBG_INIT, "thermal is %s, mode %d\n",
 		str_supported(thermal_read_mode != TPACPI_THERMAL_NONE),