Re: [PATCH] platform/x86: thinkpad_acpi: fix for incorrect fan reporting on some ThinkPad systems

From: Vishnu Sankar
Date: Fri Dec 08 2023 - 10:17:15 EST

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Hi Ilpo,

Thank you for the review

On Fri, Dec 8, 2023 at 7:53 PM Ilpo Järvinen
<ilpo.jarvinen@xxxxxxxxxxxxxxx> wrote:
>
> On Thu, 7 Dec 2023, Vishnu Sankar wrote:
>
> Hi Vishnu,
>
> Thanks for the patch.
>
> > Some ThinkPad systems ECFW use non-standard addresses for fan control
> > and reporting. This patch adds support for such ECFW so that it can report
> > the correct fan values.
> > Tested on Thinkpads L13 Yoga Gen 2 and X13 Yoga Gen 2.
> >
> > Co-developed-by: Mark Pearson <mpearson-lenovo@xxxxxxxxx>
> > Signed-off-by: Vishnu Sankar <vishnuocv@xxxxxxxxx>
>
> If Mark wrote any lines, his Signed-off-by is also required before yours,
> as per Documentation/process/5.Posting.rst, this is a hard requirement.
>
> If he only helped towards the right direction/solution but provided no
> code, I recommend using Suggested-by tag instead.
>

Ack.
Will change to Suggested-by.

> > ---
> > drivers/platform/x86/thinkpad_acpi.c | 88 ++++++++++++++++++++++++----
> > 1 file changed, 76 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c
> > index d0b5fd4137bc..51ec20e07b23 100644
> > --- a/drivers/platform/x86/thinkpad_acpi.c
> > +++ b/drivers/platform/x86/thinkpad_acpi.c
> > @@ -7950,6 +7950,11 @@ static struct ibm_struct volume_driver_data = {
> > * but the ACPI tables just mention level 7.
> > */
> >
> > +#define FAN_RPM_CAL_CONST 491520 /* FAN RPM calculation offset for some non-standard ECFW */
> > +
> > +#define FAN_NS_CTRL_STATUS BIT(2) /* Bit which determines control is enabled or not */
> > +#define FAN_NS_CTRL BIT(4) /* Bit which determines control is by host or EC */
> > +
> > enum { /* Fan control constants */
> > fan_status_offset = 0x2f, /* EC register 0x2f */
> > fan_rpm_offset = 0x84, /* EC register 0x84: LSB, 0x85 MSB (RPM)
> > @@ -7957,6 +7962,11 @@ enum { /* Fan control constants */
> > fan_select_offset = 0x31, /* EC register 0x31 (Firmware 7M)
> > bit 0 selects which fan is active */
> >
> > + fan_status_offset_ns = 0x93, /* Special status/control offset for non-standard EC Fan1 */
> > + fan2_status_offset_ns = 0x96, /* Special status/control offset for non-standard EC Fan2 */
> > + fan_rpm_status_ns = 0x95, /* Special offset for Fan1 RPM status for non-standard EC */
> > + fan2_rpm_status_ns = 0x98, /* Special offset for Fan2 RPM status for non-standard EC */
> > +
> > TP_EC_FAN_FULLSPEED = 0x40, /* EC fan mode: full speed */
> > TP_EC_FAN_AUTO = 0x80, /* EC fan mode: auto fan control */
> >
> > @@ -7967,6 +7977,7 @@ enum fan_status_access_mode {
> > TPACPI_FAN_NONE = 0, /* No fan status or control */
> > TPACPI_FAN_RD_ACPI_GFAN, /* Use ACPI GFAN */
> > TPACPI_FAN_RD_TPEC, /* Use ACPI EC regs 0x2f, 0x84-0x85 */
> > + TPACPI_FAN_RD_TPEC_NS, /* Use non-standard ACPI EC regs (eg: L13 Yoga gen2 etc.) */
> > };
> >
> > enum fan_control_access_mode {
> > @@ -7994,6 +8005,8 @@ static u8 fan_control_desired_level;
> > static u8 fan_control_resume_level;
> > static int fan_watchdog_maxinterval;
> >
> > +static bool fan_with_ns_addr;
> > +
> > static struct mutex fan_mutex;
> >
> > static void fan_watchdog_fire(struct work_struct *ignored);
> > @@ -8123,6 +8136,15 @@ static int fan_get_status(u8 *status)
> > }
> >
> > break;
> > + case TPACPI_FAN_RD_TPEC_NS:
>
> There's a big comment about FAN ACCESS MODES and now you seem to be adding
> another one. Can you please check if there would be something useful to
> add/edit in that big comment because of the addition of
> TPACPI_FAN_RD_TPEC_NS.

I will look into adding this.

>
> > + /* Default mode is AUTO which means controlled by EC */
> > + if (unlikely(!acpi_ec_read(fan_status_offset_ns, &s)))
>
> I'm skeptical that all these unlikely/likely() are useful. Some might even
> be harmful if e.g. is some error condition keeps repeating itself and
> the particular if handling that is marked with unlikely().
>
> I know the code in that file is littered with them already but it would
> be better to add into that, IMO.

I will look into this as well (removing likely/unlikely).
>
> > + return -EIO;
> > +
> > + if (likely(status))
> > + *status = s;
> > +
> > + break;
> >
> > default:
> > return -ENXIO;
> > @@ -8139,7 +8161,8 @@ static int fan_get_status_safe(u8 *status)
> > if (mutex_lock_killable(&fan_mutex))
> > return -ERESTARTSYS;
> > rc = fan_get_status(&s);
> > - if (!rc)
> > + /* NS EC doesn't have register with level settings */
> > + if (!rc && !fan_with_ns_addr)
> > fan_update_desired_level(s);
> > mutex_unlock(&fan_mutex);
> >
> > @@ -8166,7 +8189,13 @@ static int fan_get_speed(unsigned int *speed)
> >
> > if (likely(speed))
> > *speed = (hi << 8) | lo;
> > + break;
> > + case TPACPI_FAN_RD_TPEC_NS:
> > + if (unlikely(!acpi_ec_read(fan_rpm_status_ns, &lo)))
> > + return -EIO;
> >
> > + if (likely(speed))
> > + *speed = lo ? FAN_RPM_CAL_CONST / lo : 0;
> > break;
> >
> > default:
> > @@ -8178,7 +8207,7 @@ static int fan_get_speed(unsigned int *speed)
> >
> > static int fan2_get_speed(unsigned int *speed)
> > {
> > - u8 hi, lo;
> > + u8 hi, lo, status;
> > bool rc;
> >
> > switch (fan_status_access_mode) {
> > @@ -8194,7 +8223,21 @@ static int fan2_get_speed(unsigned int *speed)
> >
> > if (likely(speed))
> > *speed = (hi << 8) | lo;
> > + break;
> >
> > + case TPACPI_FAN_RD_TPEC_NS:
> > + rc = !acpi_ec_read(fan2_status_offset_ns, &status);
> > + if (rc)
> > + return -EIO;
> > + if (!(status & FAN_NS_CTRL_STATUS)) {
> > + pr_info("fan fan2 control not supported\n");
>
> Perhaps "fan2 control ..." would be enough or perhaps "secondary fan
> control ..." (the latter matching fan_init() printouts) ?

Acked

>
> > + return -EIO;
> > + }
> > + rc = !acpi_ec_read(fan2_rpm_status_ns, &lo);
> > + if (rc)
> > + return -EIO;
> > + if (likely(speed))
> > + *speed = lo ? FAN_RPM_CAL_CONST / lo : 0;
> > break;
> >
> > default:
> > @@ -8697,6 +8740,7 @@ static const struct attribute_group fan_driver_attr_group = {
> > #define TPACPI_FAN_2FAN 0x0002 /* EC 0x31 bit 0 selects fan2 */
> > #define TPACPI_FAN_2CTL 0x0004 /* selects fan2 control */
> > #define TPACPI_FAN_NOFAN 0x0008 /* no fan available */
> > +#define TPACPI_FAN_NS 0x0010 /* For EC with non-Standard register addresses */
> >
> > static const struct tpacpi_quirk fan_quirk_table[] __initconst = {
> > TPACPI_QEC_IBM('1', 'Y', TPACPI_FAN_Q1),
> > @@ -8715,6 +8759,8 @@ static const struct tpacpi_quirk fan_quirk_table[] __initconst = {
> > TPACPI_Q_LNV3('N', '2', 'O', TPACPI_FAN_2CTL), /* P1 / X1 Extreme (2nd gen) */
> > TPACPI_Q_LNV3('N', '3', '0', TPACPI_FAN_2CTL), /* P15 (1st gen) / P15v (1st gen) */
> > TPACPI_Q_LNV3('N', '3', '7', TPACPI_FAN_2CTL), /* T15g (2nd gen) */
> > + TPACPI_Q_LNV3('R', '1', 'F', TPACPI_FAN_NS), /* L13 Yoga Gen 2 */
> > + TPACPI_Q_LNV3('N', '2', 'U', TPACPI_FAN_NS), /* X13 Yoga Gen 2*/
> > TPACPI_Q_LNV3('N', '1', 'O', TPACPI_FAN_NOFAN), /* X1 Tablet (2nd gen) */
> > };
> >
> > @@ -8749,6 +8795,13 @@ static int __init fan_init(struct ibm_init_struct *iibm)
> > return -ENODEV;
> > }
> >
> > + if (quirks & TPACPI_FAN_NS) {
> > + pr_info("ECFW with non-standard fan reg control found\n");
> > + fan_with_ns_addr = 1;
> > + /* Fan ctrl support from host is undefined for now */
> > + tp_features.fan_ctrl_status_undef = 1;
> > + }
> > +
> > if (gfan_handle) {
> > /* 570, 600e/x, 770e, 770x */
> > fan_status_access_mode = TPACPI_FAN_RD_ACPI_GFAN;
> > @@ -8756,11 +8809,13 @@ static int __init fan_init(struct ibm_init_struct *iibm)
> > /* all other ThinkPads: note that even old-style
> > * ThinkPad ECs supports the fan control register */
> > if (likely(acpi_ec_read(fan_status_offset,
> > - &fan_control_initial_status))) {
> > + &fan_control_initial_status)) || fan_with_ns_addr) {
>
> So if we know the addresses are non-standard, why is the acpi_ec_read
> performed at all? That is, why isn't the || logic in reverse order?
>
Agreed.
I will change the logic to reverse order.

> I also wonder what will fan_control_initial_status be set to in this case,
> is it garbage?

0x84 is still a valid register (but not related to Fan)

>
> > int res;
> > unsigned int speed;
> >
> > - fan_status_access_mode = TPACPI_FAN_RD_TPEC;
> > + fan_status_access_mode = fan_with_ns_addr ?
> > + TPACPI_FAN_RD_TPEC_NS : TPACPI_FAN_RD_TPEC;
> > +
> > if (quirks & TPACPI_FAN_Q1)
> > fan_quirk1_setup();
> > /* Try and probe the 2nd fan */
> > @@ -8769,7 +8824,8 @@ static int __init fan_init(struct ibm_init_struct *iibm)
> > if (res >= 0 && speed != FAN_NOT_PRESENT) {
> > /* It responded - so let's assume it's there */
> > tp_features.second_fan = 1;
> > - tp_features.second_fan_ctl = 1;
> > + /* fan control not currently available for ns ECFW */
> > + tp_features.second_fan_ctl = fan_with_ns_addr ? 0 : 1;
>
> = !fan_with_ns_addr;

Agreed.

>
> > pr_info("secondary fan control detected & enabled\n");
> > } else {
> > /* Fan not auto-detected */
> > @@ -8944,6 +9000,7 @@ static int fan_read(struct seq_file *m)
> > str_enabled_disabled(status), status);
> > break;
> >
> > + case TPACPI_FAN_RD_TPEC_NS:
> > case TPACPI_FAN_RD_TPEC:
> > /* all except 570, 600e/x, 770e, 770x */
> > rc = fan_get_status_safe(&status);
> > @@ -8958,13 +9015,20 @@ static int fan_read(struct seq_file *m)
> >
> > seq_printf(m, "speed:\t\t%d\n", speed);
> >
> > - if (status & TP_EC_FAN_FULLSPEED)
> > - /* Disengaged mode takes precedence */
> > - seq_printf(m, "level:\t\tdisengaged\n");
> > - else if (status & TP_EC_FAN_AUTO)
> > - seq_printf(m, "level:\t\tauto\n");
> > - else
> > - seq_printf(m, "level:\t\t%d\n", status);
> > + if (fan_status_access_mode == TPACPI_FAN_RD_TPEC_NS) {
> > + /* No full speed bit in NS EC*/
>
> Missing space. But I'd convert these two comments into a multiline one
> anyway.
>
Acked

> > + /* EC Auto mode is set by default. No other levels settings available*/
> > + (status & FAN_NS_CTRL) ? seq_puts(m, "level:\t\tunknown\n")
> > + : seq_puts(m, "level:\t\tauto\n");
>
> seq_printf(m, "level:\t\t%s\n", status & FAN_NS_CTRL ? "unknown" : "auto");
>

Acked.

> > + } else {
> > + if (status & TP_EC_FAN_FULLSPEED)
> > + /* Disengaged mode takes precedence */
> > + seq_puts(m, "level:\t\tdisengaged\n");
> > + else if (status & TP_EC_FAN_AUTO)
> > + seq_puts(m, "level:\t\tauto\n");
>
> Please don't make an unrelated seq_printf() -> seq_puts() change in this
> patch.

Ack.
(The checkpatch.pl threw a warning regarding seq_printf() for these
lines after the changes I made.)

>
> > + else
> > + seq_printf(m, "level:\t\t%d\n", status);
> > + }
> > break;
> >
> > case TPACPI_FAN_NONE:
> >
>
> --
> i.
>

Thank you for correcting these and Apologize for any inconvenience caused.
I have noted the comments. Will share the updated patch soon.

--

Regards,

Vishnu Sankar
+817015150407 (Japan)

Next message: Marek Behún: "Re: [PATCH v2 0/3] Moxtet bus fixes"
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In reply to: Mark Pearson: "Re: [PATCH] platform/x86: thinkpad_acpi: fix for incorrect fan reporting on some ThinkPad systems"
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