On Sun, 23 Mar 2025, Seyediman Seyedarab wrote:

Hi,

Thanks for looking into reaching conclusion for this issue.

From: Eduard Christian Dumitrescu eduard.c.dumitrescu@gmail.com

The bug was introduced in commit 57d0557dfa49 ("platform/x86:

the commit

thinkpad_acpi: Add Thinkpad Edge E531 fan support") which adds a new fan control method via the FANG and FANW ACPI methods.

T945, T495s, and E560 laptops have the FANG+FANW ACPI methods (therefore fang_handle and fanw_handle are not NULL) but they do not actually work, which results in the dreaded "No such device or address" error.

Please put the first paragraph about the commit 57d0557dfa49 here now that you've state what the problem/bug is first. You can make them to be one joined paragraph.

Fan access and control is restored after forcing the legacy non-ACPI fan control method by setting both fang_handle and fanw_handle to NULL.

The DSDT table code for the FANG+FANW methods doesn't seem to do anything special regarding the fan being secondary.

This patch adds a quirk for T495, T495s, and E560 to make them avoid the FANG/FANW methods.

We avoid phrases like "This patch ...", so start with "Add a quirk ..." Also, this should be before "Fan access ..." sentence to make this description more logical (again make them to be part of a same paragraph).

Cc: stable@vger.kernel.org Fixes: 57d0557dfa49 ("platform/x86: thinkpad_acpi: Add Thinkpad Edge E531 fan support") Reported-by: Vlastimil Holer vlastimil.holer@gmail.com Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219643

I'd prefer these tags to be in this order:

Reported-by: Fixes: Closes: Cc: stable@vger.kernel.org

ss it's a bit more logical.

Tested-by: crok crok.bic@gmail.com Tested-by: Alireza Elikahi scr0lll0ck1s4b0v3h0m3k3y@gmail.com

Did these two person either give you those Tested-by tags or gave you green light to add theirs Tested-by tags? I don't see the tags given in the bugzilla entry. If they didn't yet, please ask if they're fine with you adding their Tested-by tags.

In kernel development, in general, we're more than happy credit people who invested their time in testing changes but that being said, we don't invent Tested-by tags just from the fact that we know somebody has tested a patch.

When respinning v3, please remember to add Kurt's Reviewed-by tag too as maintainer's tools only automatically collect them for the most recent version so when sending the next version, you need to add them into the submission.

Signed-off-by: Eduard Christian Dumitrescu eduard.c.dumitrescu@gmail.com Co-developed-by: Seyediman Seyedarab ImanDevel@gmail.com Signed-off-by: Seyediman Seyedarab ImanDevel@gmail.com

---

Changes in v2:

• Added the From: tag for the original author
• Replaced the Co-authored-by tag with Co-developed-by
• Cc'd stable@vger.kernel.org
• Removed the extra space inside the comment
• Dropped nullification of sfan/gfan_handle, as it's unrelated to the current fix

Kindest Regards, Seyediman

drivers/platform/x86/thinkpad_acpi.c | 11 +++++++++++ 1 file changed, 11 insertions(+)

diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c index d8df1405edfa..27fd67a2f2d1 100644 --- a/drivers/platform/x86/thinkpad_acpi.c +++ b/drivers/platform/x86/thinkpad_acpi.c @@ -8793,6 +8793,7 @@ static const struct attribute_group fan_driver_attr_group = { #define TPACPI_FAN_NS 0x0010 /* For EC with non-Standard register addresses */ #define TPACPI_FAN_DECRPM 0x0020 /* For ECFW's with RPM in register as decimal */ #define TPACPI_FAN_TPR 0x0040 /* Fan speed is in Ticks Per Revolution */ +#define TPACPI_FAN_NOACPI 0x0080 /* Don't use ACPI methods even if detected */ static const struct tpacpi_quirk fan_quirk_table[] __initconst = { TPACPI_QEC_IBM('1', 'Y', TPACPI_FAN_Q1), @@ -8823,6 +8824,9 @@ static const struct tpacpi_quirk fan_quirk_table[] __initconst = { TPACPI_Q_LNV3('N', '1', 'O', TPACPI_FAN_NOFAN), /* X1 Tablet (2nd gen) */ TPACPI_Q_LNV3('R', '0', 'Q', TPACPI_FAN_DECRPM),/* L480 */ TPACPI_Q_LNV('8', 'F', TPACPI_FAN_TPR), /* ThinkPad x120e */

• TPACPI_Q_LNV3('R', '0', '0', TPACPI_FAN_NOACPI),/* E560 */
• TPACPI_Q_LNV3('R', '1', '2', TPACPI_FAN_NOACPI),/* T495 */
• TPACPI_Q_LNV3('R', '1', '3', TPACPI_FAN_NOACPI),/* T495s */

}; static int __init fan_init(struct ibm_init_struct *iibm) @@ -8874,6 +8878,13 @@ static int __init fan_init(struct ibm_init_struct *iibm) tp_features.fan_ctrl_status_undef = 1; }

• if (quirks & TPACPI_FAN_NOACPI) {

• /* E560, T495, T495s */
  

• pr_info("Ignoring buggy ACPI fan access method\n");
  

• fang_handle = NULL;
  

• fanw_handle = NULL;
  

• }
• if (gfan_handle) { /* 570, 600e/x, 770e, 770x */ fan_status_access_mode = TPACPI_FAN_RD_ACPI_GFAN;

The code change itself looks fine.