* [PATCH v2] power: sequencing: pcie-m2: Match WCN6855 and WCN7851 UART BT variants by subdevice ID
@ 2026-07-23 3:34 Wei Deng
2026-07-23 3:43 ` sashiko-bot
0 siblings, 1 reply; 2+ messages in thread
From: Wei Deng @ 2026-07-23 3:34 UTC (permalink / raw)
To: Manivannan Sadhasivam, Bartosz Golaszewski
Cc: linux-pci, linux-pm, linux-kernel, quic_chezhou, cheng.jiang,
shuai.zhang, jinwang.li, xiuzhuo.shang, mengshi.wu, Wei Deng
The WCN6855 and WCN7851 combo chips are available in M.2 card variants
that differ by their BT interface: some expose BT over UART while others
expose BT over USB. Both variants use the same PCIe device ID for the
WiFi interface, distinguished only by their sub-system device ID.
The bare PCI_DEVICE() entries match all sub-system IDs, so both UART and
USB variants hit the same table entry and trigger UART serdev creation.
For USB variants this is wrong — there is no UART BT interface on such
a card, and the serdev probe will fail.
Narrow the matches to UART variants only by using PCI_DEVICE_SUB with
their respective sub-system IDs, so USB variants no longer trigger
UART serdev creation.
Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
Signed-off-by: Wei Deng <wei.deng@oss.qualcomm.com>
---
Changes in v2:
- Send this patch independently, at Bartosz's request.
- Update commit message.
- Collect Reviewed-by: Manivannan Sadhasivam.
Link: https://lore.kernel.org/all/20260709-fix-hamoa-m2-w-disable2-v1-2-5e725091266a@oss.qualcomm.com/
---
drivers/power/sequencing/pwrseq-pcie-m2.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/power/sequencing/pwrseq-pcie-m2.c b/drivers/power/sequencing/pwrseq-pcie-m2.c
index 26f695b98d2b..5dfc9f9ef64f 100644
--- a/drivers/power/sequencing/pwrseq-pcie-m2.c
+++ b/drivers/power/sequencing/pwrseq-pcie-m2.c
@@ -192,9 +192,11 @@ static const struct pci_device_id pwrseq_m2_pci_ids[] = {
.driver_data = (kernel_ulong_t)"nxp,88w8987-bt" },
{ PCI_DEVICE_SUB(PCI_VENDOR_ID_QCOM, 0x1103, PCI_VENDOR_ID_QCOM, 0x0108),
.driver_data = (kernel_ulong_t)"qcom,qca2066-bt" },
- { PCI_DEVICE(PCI_VENDOR_ID_QCOM, 0x1103),
+ { PCI_DEVICE_SUB(PCI_VENDOR_ID_QCOM, 0x1103, PCI_VENDOR_ID_FOXCONN, 0xe105),
.driver_data = (kernel_ulong_t)"qcom,wcn6855-bt" },
- { PCI_DEVICE(PCI_VENDOR_ID_QCOM, 0x1107),
+ { PCI_DEVICE_SUB(PCI_VENDOR_ID_QCOM, 0x1103, PCI_VENDOR_ID_QCOM, 0x337e),
+ .driver_data = (kernel_ulong_t)"qcom,wcn6855-bt" },
+ { PCI_DEVICE_SUB(PCI_VENDOR_ID_QCOM, 0x1107, PCI_VENDOR_ID_QCOM, 0x337c),
.driver_data = (kernel_ulong_t)"qcom,wcn7850-bt" },
{ PCI_DEVICE(PCI_VENDOR_ID_QCOM, 0x1112),
.driver_data = (kernel_ulong_t)"qcom,qcc2072-bt" },
---
base-commit: 162ea02941a936f8899f3dbe10607b1d5af1b07b
change-id: 20260723-hamoa-m2-sub-id-v2-f8640ac2520d
Best regards,
--
Wei Deng <wei.deng@oss.qualcomm.com>
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH v2] power: sequencing: pcie-m2: Match WCN6855 and WCN7851 UART BT variants by subdevice ID
2026-07-23 3:34 [PATCH v2] power: sequencing: pcie-m2: Match WCN6855 and WCN7851 UART BT variants by subdevice ID Wei Deng
@ 2026-07-23 3:43 ` sashiko-bot
0 siblings, 0 replies; 2+ messages in thread
From: sashiko-bot @ 2026-07-23 3:43 UTC (permalink / raw)
To: Wei Deng; +Cc: linux-pci
> The WCN6855 and WCN7851 combo chips are available in M.2 card variants
> that differ by their BT interface: some expose BT over UART while others
> expose BT over USB. Both variants use the same PCIe device ID for the
> WiFi interface, distinguished only by their sub-system device ID.
>
> The bare PCI_DEVICE() entries match all sub-system IDs, so both UART and
> USB variants hit the same table entry and trigger UART serdev creation.
> For USB variants this is wrong — there is no UART BT interface on such
> a card, and the serdev probe will fail.
>
> Narrow the matches to UART variants only by using PCI_DEVICE_SUB with
> their respective sub-system IDs, so USB variants no longer trigger
> UART serdev creation.
>
> Reviewed-by: Manivannan Sadhasivam <mani@kernel.org>
> Signed-off-by: Wei Deng <wei.deng@oss.qualcomm.com>
Sashiko has reviewed this patch and found no issues. It looks great!
--
Sashiko AI review · https://sashiko.dev/#/patchset/20260723-hamoa-m2-sub-id-v2-v2-1-f10f95eb9ebf@oss.qualcomm.com?part=1
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2026-07-23 3:43 UTC | newest]
Thread overview: 2+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-07-23 3:34 [PATCH v2] power: sequencing: pcie-m2: Match WCN6855 and WCN7851 UART BT variants by subdevice ID Wei Deng
2026-07-23 3:43 ` sashiko-bot
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox