From: Baochen Qiang quic_bqiang@quicinc.com
[ Upstream commit ce8669a27016354dfa8bf3c954255cb9f3583bae ]
To handle the Lenovo unexpected wakeup issue [1], previously we revert commit 166a490f59ac ("wifi: ath11k: support hibernation"). So currently WLAN target is put into WoWLAN mode during suspend. This is a temporary solution as it does not work on machines where WLAN power is cut off.
The thought here is that we do WoWLAN suspend on Lenovo machines while do non-WoWLAN suspend (which is done in the reverted commit) on other machines. This requires us to identify Lenovo machines from others. For that purpose, read board vendor and product name from DMI interface, match it against all known affected machines. If there is a match, choose WoWLAN suspend mode, else choose non-WoWLAN mode. Save the mode in ab for later reference.
[1] https://bugzilla.kernel.org/show_bug.cgi?id=219196
Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.30
Tested-by: Muhammad Usama Anjum usama.anjum@collabora.com Tested-by: Takashi Iwai tiwai@suse.de Signed-off-by: Baochen Qiang quic_bqiang@quicinc.com Link: https://patch.msgid.link/20250328-ath11k-bring-hibernation-back-v3-1-23405ae... Signed-off-by: Jeff Johnson jeff.johnson@oss.qualcomm.com Signed-off-by: Sasha Levin sashal@kernel.org ---
**YES** This commit should definitely be backported to stable kernel trees. Here's my detailed analysis: ## Bug Fix Nature This commit clearly fixes a specific user-visible bug affecting Lenovo laptops with WiFi suspend/wake functionality. The commit message explicitly references bugzilla.kernel.org issue #219196, indicating this addresses real user complaints about unexpected wakeup behavior. This aligns perfectly with the **YES** backport example (Similar Commit #1) which also reverted hibernation support due to Lenovo platform suspend issues. ## Code Changes Analysis ### 1. DMI Quirk Table Addition ```c +static const struct dmi_system_id ath11k_pm_quirk_table[] = { + { + .driver_data = (void *)ATH11K_PM_WOW, + .matches = { + DMI_MATCH(DMI_BOARD_VENDOR, "LENOVO"), + DMI_MATCH(DMI_PRODUCT_NAME, "21J4"), + }, + }, ``` This is a standard, low-risk pattern used throughout the kernel for hardware-specific workarounds. It only affects machines that exactly match the DMI criteria. ### 2. PM Policy Infrastructure ```c +enum ath11k_pm_policy { + ATH11K_PM_DEFAULT, + ATH11K_PM_WOW, +}; ``` The commit adds a simple enum and uses existing WoWLAN suspend mechanisms rather than introducing new power management code. ### 3. Policy Selection Logic ```c + dmi_id = dmi_first_match(ath11k_pm_quirk_table); + if (dmi_id) + ab->pm_policy = (kernel_ulong_t)dmi_id->driver_data; + else + ab->pm_policy = ATH11K_PM_DEFAULT; ``` This is straightforward DMI matching that sets a policy flag without changing core functionality. ## Risk Assessment **Extremely Low Risk:** - **Scope**: Only affects specific Lenovo laptop models (21J4, 21K4, 21K6, 21K8, 21KA, 21F9) - **Fallback**: Non-matching machines continue using existing default behavior - **Tested Path**: WoWLAN suspend mode is already implemented and working - **No Core Changes**: Doesn't modify suspend/resume logic, just selects which path to use ## Comparison to Reference Commits This follows the same pattern as **Similar Commit #1** (marked YES), which also addressed Lenovo platform suspend issues by reverting hibernation support. Both commits: - Target specific hardware compatibility issues - Use conservative approaches (WoWLAN vs full hibernation) - Have minimal code footprint - Address real user bug reports Unlike the **NO** examples which add new features (WoWLAN support, new suspend capabilities), this commit uses existing infrastructure to fix hardware-specific incompatibilities. ## Stable Tree Criteria Alignment ✅ **Fixes important bugs** - Suspend/wake functionality on laptops ✅ **Small and contained** - Only DMI table and policy selection ✅ **Low regression risk** - Targeted to specific hardware ✅ **User-visible impact** - Improves power management behavior ✅ **No architectural changes** - Uses existing WoWLAN mechanisms This is an ideal stable backport candidate that fixes real user issues with minimal risk.
drivers/net/wireless/ath/ath11k/core.c | 55 ++++++++++++++++++++++++++ drivers/net/wireless/ath/ath11k/core.h | 7 ++++ 2 files changed, 62 insertions(+)
diff --git a/drivers/net/wireless/ath/ath11k/core.c b/drivers/net/wireless/ath/ath11k/core.c index 3d39ff85ba94a..f3a29f5d2381b 100644 --- a/drivers/net/wireless/ath/ath11k/core.c +++ b/drivers/net/wireless/ath/ath11k/core.c @@ -907,6 +907,52 @@ static const struct ath11k_hw_params ath11k_hw_params[] = { }, };
+static const struct dmi_system_id ath11k_pm_quirk_table[] = { + { + .driver_data = (void *)ATH11K_PM_WOW, + .matches = { + DMI_MATCH(DMI_BOARD_VENDOR, "LENOVO"), + DMI_MATCH(DMI_PRODUCT_NAME, "21J4"), + }, + }, + { + .driver_data = (void *)ATH11K_PM_WOW, + .matches = { + DMI_MATCH(DMI_BOARD_VENDOR, "LENOVO"), + DMI_MATCH(DMI_PRODUCT_NAME, "21K4"), + }, + }, + { + .driver_data = (void *)ATH11K_PM_WOW, + .matches = { + DMI_MATCH(DMI_BOARD_VENDOR, "LENOVO"), + DMI_MATCH(DMI_PRODUCT_NAME, "21K6"), + }, + }, + { + .driver_data = (void *)ATH11K_PM_WOW, + .matches = { + DMI_MATCH(DMI_BOARD_VENDOR, "LENOVO"), + DMI_MATCH(DMI_PRODUCT_NAME, "21K8"), + }, + }, + { + .driver_data = (void *)ATH11K_PM_WOW, + .matches = { + DMI_MATCH(DMI_BOARD_VENDOR, "LENOVO"), + DMI_MATCH(DMI_PRODUCT_NAME, "21KA"), + }, + }, + { + .driver_data = (void *)ATH11K_PM_WOW, + .matches = { + DMI_MATCH(DMI_BOARD_VENDOR, "LENOVO"), + DMI_MATCH(DMI_PRODUCT_NAME, "21F9"), + }, + }, + {} +}; + static inline struct ath11k_pdev *ath11k_core_get_single_pdev(struct ath11k_base *ab) { WARN_ON(!ab->hw_params.single_pdev_only); @@ -2327,8 +2373,17 @@ EXPORT_SYMBOL(ath11k_core_pre_init);
int ath11k_core_init(struct ath11k_base *ab) { + const struct dmi_system_id *dmi_id; int ret;
+ dmi_id = dmi_first_match(ath11k_pm_quirk_table); + if (dmi_id) + ab->pm_policy = (kernel_ulong_t)dmi_id->driver_data; + else + ab->pm_policy = ATH11K_PM_DEFAULT; + + ath11k_dbg(ab, ATH11K_DBG_BOOT, "pm policy %u\n", ab->pm_policy); + ret = ath11k_core_soc_create(ab); if (ret) { ath11k_err(ab, "failed to create soc core: %d\n", ret); diff --git a/drivers/net/wireless/ath/ath11k/core.h b/drivers/net/wireless/ath/ath11k/core.h index 1a3d0de4afde8..df2b0cb2f0b5a 100644 --- a/drivers/net/wireless/ath/ath11k/core.h +++ b/drivers/net/wireless/ath/ath11k/core.h @@ -892,6 +892,11 @@ struct ath11k_msi_config { u16 hw_rev; };
+enum ath11k_pm_policy { + ATH11K_PM_DEFAULT, + ATH11K_PM_WOW, +}; + /* Master structure to hold the hw data which may be used in core module */ struct ath11k_base { enum ath11k_hw_rev hw_rev; @@ -1058,6 +1063,8 @@ struct ath11k_base { } testmode; #endif
+ enum ath11k_pm_policy pm_policy; + /* must be last */ u8 drv_priv[] __aligned(sizeof(void *)); };