On 11/20/2023 2:15 AM, Kang Yang wrote:
> On some platforms it's not possible to allocate 32 MSI vectors for
> various reasons, maybe kernel configuration, VT-d disabled, buggy BIOS
> etc. So ath12k was not able to use WCN7850 PCI devices on those
> platforms. Add support for one MSI vector to solve that.
>
> In case of one MSI vector, interrupt migration needs to be disabled.
> This is because when interrupt migration happens, the msi_data may
> change. However, msi_data is already programmed to rings during initial
> phase and ath12k has no way to know that msi_data is changed during run
> time and reprogram again.
>
> In case of one MSI vector, MHI subsystem should not use IRQF_NO_SUSPEND
> as WCN7850 doesn't set this flag too. Ath12k doesn't need to leave IRQ
> enabled in suspend state.
>
> Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4
>
> Signed-off-by: Kang Yang <quic_kangyang@xxxxxxxxxxx>
> ---
> drivers/net/wireless/ath/ath12k/mhi.c | 16 +++++++--
> drivers/net/wireless/ath/ath12k/pci.c | 51 ++++++++++++++++++++-------
> 2 files changed, 52 insertions(+), 15 deletions(-)
...
> diff --git a/drivers/net/wireless/ath/ath12k/pci.c b/drivers/net/wireless/ath/ath12k/pci.c
> index 3bb2d622dc52..4484bac18f4e 100644
> --- a/drivers/net/wireless/ath/ath12k/pci.c
> +++ b/drivers/net/wireless/ath/ath12k/pci.c
...
> @@ -713,18 +731,26 @@ static int ath12k_pci_msi_alloc(struct ath12k_pci *ab_pci)
> msi_config->total_vectors,
> msi_config->total_vectors,
> PCI_IRQ_MSI);
> - if (num_vectors != msi_config->total_vectors) {
> - ath12k_err(ab, "failed to get %d MSI vectors, only %d available",
> - msi_config->total_vectors, num_vectors);
>
> - if (num_vectors >= 0)
> - return -EINVAL;
> - else
> - return num_vectors;
> - } else {
> + if (num_vectors == msi_config->total_vectors) {
> set_bit(ATH12K_PCI_FLAG_MULTI_MSI_VECTORS, &ab_pci->flags);
> ab_pci->irq_flags = IRQF_SHARED;
> + } else {
> + num_vectors = pci_alloc_irq_vectors(ab_pci->pdev,
> + 1,
> + 1,
> + PCI_IRQ_MSI);
> + if (num_vectors < 0) {
> + ret = -EINVAL;
> + goto reset_msi_config;
> + }
> + clear_bit(ATH12K_PCI_FLAG_MULTI_MSI_VECTORS, &ab_pci->flags);
> + ab_pci->msi_config = &msi_config_one_msi;
> + ab_pci->irq_flags = IRQF_SHARED | IRQF_NOBALANCING;
> + ath12k_dbg(ab, ATH12K_DBG_PCI, "request MSI one vector\n");
> +
ath12k-check is flagging this:
drivers/net/wireless/ath/ath12k/pci.c:761: Blank lines aren't necessary
before a close brace '}'
<
> }
> + ath12k_info(ab, "MSI vectors: %d\n", num_vectors);
>
> ath12k_pci_msi_disable(ab_pci);
>
