[RFT rtw-next] wifi: rtw88: add quirks to disable PCI ASPM for HP P3S95EA#ACB

[RFT rtw-next] wifi: rtw88: add quirks to disable PCI ASPM for HP P3S95EA#ACB

[Ping-Ke Shih]

On an HP laptop (P3S95EA#ACB) equipped with a Realtek RTL8821CE 802.11ac
PCIe adapter (PCI ID: 10ec:c821), the system experiences a hard lockup
(complete freeze of the UI and kernel, sysrq doesn't work, requires
holding the power button) when the WiFi adapter enters the power
saving state.

Add a quirk to disable ASPM.

Reported-by: LB F <goainwo@gmail.com>
Closes: https://lore.kernel.org/linux-wireless/CALdGYqSQ1Ko2TTBhUizMu_FvLMUAuQfFrVwS10n_C-LSQJQQkQ@mail.gmail.com/
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
---
 drivers/net/wireless/realtek/rtw88/pci.c | 30 ++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c
index ec0a45bfb670..0b60a0ce96a1 100644
--- a/drivers/net/wireless/realtek/rtw88/pci.c
+++ b/drivers/net/wireless/realtek/rtw88/pci.c
@@ -2,6 +2,7 @@
 /* Copyright(c) 2018-2019  Realtek Corporation
  */
 
+#include <linux/dmi.h>
 #include <linux/module.h>
 #include <linux/pci.h>
 #include "main.h"
@@ -1744,6 +1745,34 @@ const struct pci_error_handlers rtw_pci_err_handler = {
 };
 EXPORT_SYMBOL(rtw_pci_err_handler);
 
+enum rtw88_quirk_dis_pci_caps {
+	QUIRK_DIS_PCI_CAP_ASPM,
+};
+
+static int disable_pci_caps(const struct dmi_system_id *dmi)
+{
+	uintptr_t dis_caps = (uintptr_t)dmi->driver_data;
+
+	if (dis_caps & BIT(QUIRK_DIS_PCI_CAP_ASPM))
+		rtw_pci_disable_aspm = true;
+
+	return 1;
+}
+
+static const struct dmi_system_id rtw88_pci_quirks[] = {
+	{
+		.callback = disable_pci_caps,
+		.ident = "HP Notebook - P3S95EA#ACB",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "HP Notebook"),
+			DMI_MATCH(DMI_PRODUCT_SKU, "P3S95EA#ACB"),
+		},
+		.driver_data = (void *)BIT(QUIRK_DIS_PCI_CAP_ASPM),
+	},
+	{}
+};
+
 int rtw_pci_probe(struct pci_dev *pdev,
 		  const struct pci_device_id *id)
 {
@@ -1808,6 +1837,7 @@ int rtw_pci_probe(struct pci_dev *pdev,
 	    bridge && bridge->vendor == PCI_VENDOR_ID_INTEL)
 		rtwpci->rx_no_aspm = true;
 
+	dmi_check_system(rtw88_pci_quirks);
 	rtw_pci_phy_cfg(rtwdev);
 
 	ret = rtw_register_hw(rtwdev, hw);
-- 
2.25.1

Re: [RFT rtw-next] wifi: rtw88: add quirks to disable PCI ASPM for HP P3S95EA#ACB

[LB F]

Hi Ping-Ke,

I successfully applied your patch out-of-tree and performed rigorous
testing on the host machine.

I can officially confirm that the patch works flawlessly. The DMI
quirk triggered correctly and successfully prevented the
hardware-level PCIe bus lockups on my HP P3S95EA#ACB.

Testing Environment & Methodology:
- Kernel: CachyOS Linux 6.19.6-2-cachyos x86_64
- Toolchain: Clang/LLVM 21.1.8 (`make CC=clang LLVM=1 modules`)
- Extraction: We fetched the strict
`drivers/net/wireless/realtek/rtw88` sub-tree out of the
torvalds/linux `v6.19` tree utilizing `git sparse-checkout` to cleanly
apply the patch without having to compile the entire 2.5GB+ kernel.
- The resulting `.ko` object files were compressed to `.zst` and
installed successfully over the generic CachyOS system driver objects.

Verification Conditions:
- Removed ALL local workarounds. `disable_aspm=Y` is no longer forced
via `/etc/modprobe.d/` overrides.
- Power saving remains natively ON `wifi.powersave = 3` (managed by
NetworkManager).
- Left the laptop in multiple 5-10 minute complete idle states to
enforce sleep modes.

Post-Boot Log Analysis & Potential Improvement Proposition:
The system remained 100% stable without any kernel panics or UI freezes.
However, I continuously monitored the `dmesg` ring buffer and noticed
an intriguing behavior. While the laptop sits completely idle
(NetworkManager connected, but no active traffic), the `rtw88` driver
starts flooded the logs with thousands of firmware errors:

[ 1084.746485] rtw88_8821ce 0000:13:00.0: firmware failed to leave lps state
[ 1084.749662] rtw88_8821ce 0000:13:00.0: failed to send h2c command
[ 1084.752895] rtw88_8821ce 0000:13:00.0: failed to send h2c command

If my understanding of this architecture is correct, previously, when
ASPM wasn't disabled, this exact failure of the adapter firmare inside
`LPS_DEEP_MODE_LCLK` would violently lock up the PCIe bus and crash
the host. Now, thanks to your DMI ASPM quirk at the `rtw88_pci` level,
the host PCIe controller doesn't enter `L1` and is perfectly shielded
from the adapter locking itself up! The OS handles the timeouts
gracefully and driver recovery prevents a hard freeze.

A question for your consideration: Given the immense volume of these
`h2c` timeout errors (and the underlying firmware's fundamental
inability to cleanly enter/exit its own sleep states without L1
participation on this HP model), do you think it would be beneficial
to *also* dynamically disable LPS Deep sleep when this specific ASPM
quirk is triggered?

For example, dynamically forcing `rtwdev->lps_conf.deep_mode =
LPS_DEEP_MODE_NONE` when the DMI ASPM flag is active, strictly to
prevent the firmware from attempting a sleep cycle that is doomed to
fail and polluting the queues and logs? Perhaps this might also save
microscopic CPU interrupts from continuous H2C polling timeouts?

If you believe that simply letting the driver recover and tolerating
the error spam in `dmesg` is the preferred/safer upstream approach, I
am perfectly happy. The patch functions as advertised and system
stability is unequivocally restored!

Thank you immensely for your rapid debugging and definitive patch for
this long-standing issue and for bringing stability to this model.

Tested-by: Oleksandr Havrylov <goainwo@gmail.com>

*(Note: I was a bit unsure which of the two active mailing list
threads was the most appropriate place for this final report — the
original bug discussion or the new RFT patch submission thread — so I
replied to both just to ensure it is correctly attached to the patch.
Apologies for the duplicate email!)*

Best regards,
Oleksandr Havrylov

ср, 11 мар. 2026 г. в 04:08, Ping-Ke Shih <pkshih@realtek.com>:
>
> On an HP laptop (P3S95EA#ACB) equipped with a Realtek RTL8821CE 802.11ac
> PCIe adapter (PCI ID: 10ec:c821), the system experiences a hard lockup
> (complete freeze of the UI and kernel, sysrq doesn't work, requires
> holding the power button) when the WiFi adapter enters the power
> saving state.
>
> Add a quirk to disable ASPM.
>
> Reported-by: LB F <goainwo@gmail.com>
> Closes: https://lore.kernel.org/linux-wireless/CALdGYqSQ1Ko2TTBhUizMu_FvLMUAuQfFrVwS10n_C-LSQJQQkQ@mail.gmail.com/
> Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
> ---
>  drivers/net/wireless/realtek/rtw88/pci.c | 30 ++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
>
> diff --git a/drivers/net/wireless/realtek/rtw88/pci.c b/drivers/net/wireless/realtek/rtw88/pci.c
> index ec0a45bfb670..0b60a0ce96a1 100644
> --- a/drivers/net/wireless/realtek/rtw88/pci.c
> +++ b/drivers/net/wireless/realtek/rtw88/pci.c
> @@ -2,6 +2,7 @@
>  /* Copyright(c) 2018-2019  Realtek Corporation
>   */
>
> +#include <linux/dmi.h>
>  #include <linux/module.h>
>  #include <linux/pci.h>
>  #include "main.h"
> @@ -1744,6 +1745,34 @@ const struct pci_error_handlers rtw_pci_err_handler = {
>  };
>  EXPORT_SYMBOL(rtw_pci_err_handler);
>
> +enum rtw88_quirk_dis_pci_caps {
> +       QUIRK_DIS_PCI_CAP_ASPM,
> +};
> +
> +static int disable_pci_caps(const struct dmi_system_id *dmi)
> +{
> +       uintptr_t dis_caps = (uintptr_t)dmi->driver_data;
> +
> +       if (dis_caps & BIT(QUIRK_DIS_PCI_CAP_ASPM))
> +               rtw_pci_disable_aspm = true;
> +
> +       return 1;
> +}
> +
> +static const struct dmi_system_id rtw88_pci_quirks[] = {
> +       {
> +               .callback = disable_pci_caps,
> +               .ident = "HP Notebook - P3S95EA#ACB",
> +               .matches = {
> +                       DMI_MATCH(DMI_SYS_VENDOR, "HP"),
> +                       DMI_MATCH(DMI_PRODUCT_NAME, "HP Notebook"),
> +                       DMI_MATCH(DMI_PRODUCT_SKU, "P3S95EA#ACB"),
> +               },
> +               .driver_data = (void *)BIT(QUIRK_DIS_PCI_CAP_ASPM),
> +       },
> +       {}
> +};
> +
>  int rtw_pci_probe(struct pci_dev *pdev,
>                   const struct pci_device_id *id)
>  {
> @@ -1808,6 +1837,7 @@ int rtw_pci_probe(struct pci_dev *pdev,
>             bridge && bridge->vendor == PCI_VENDOR_ID_INTEL)
>                 rtwpci->rx_no_aspm = true;
>
> +       dmi_check_system(rtw88_pci_quirks);
>         rtw_pci_phy_cfg(rtwdev);
>
>         ret = rtw_register_hw(rtwdev, hw);
> --
> 2.25.1
>