On Mon, 23 Aug 2021 17:40:31 +0100,
Pali Rohár <pali@xxxxxxxxxx> wrote:
>
> Experiments showed that in register PCIE_MSI_PAYLOAD_REG is stored number
> of the last received MSI interrupt and not number of MSI interrupt which
> belongs to msi_idx bit. Therefore this implies that aardvark HW can cache
> only bits [4:0] of received MSI interrupts with effectively means that it
> supports only MSI interrupts with numbers 0-31.
>
> Do not read PCIE_MSI_PAYLOAD_REG register for determining MSI interrupt
> number. Instead ensure that pci-aardvark.c configures only MSI numbers in
> range 0-31 and then msi_idx contains correct received MSI number.
>
> Signed-off-by: Pali Rohár <pali@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> ---
> drivers/pci/controller/pci-aardvark.c | 11 +++--------
> 1 file changed, 3 insertions(+), 8 deletions(-)
>
> diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
> index 48fbfa7eb24c..81c4a9ff91a3 100644
> --- a/drivers/pci/controller/pci-aardvark.c
> +++ b/drivers/pci/controller/pci-aardvark.c
> @@ -1232,7 +1232,6 @@ static void advk_pcie_remove_irq_domain(struct advk_pcie *pcie)
> static void advk_pcie_handle_msi(struct advk_pcie *pcie)
> {
> u32 msi_val, msi_mask, msi_status, msi_idx;
> - u16 msi_data;
> int virq;
>
> msi_mask = advk_readl(pcie, PCIE_MSI_MASK_REG);
> @@ -1243,17 +1242,13 @@ static void advk_pcie_handle_msi(struct advk_pcie *pcie)
> if (!(BIT(msi_idx) & msi_status))
> continue;
>
> - /*
> - * msi_idx contains bits [4:0] of the msi_data and msi_data
> - * contains 16bit MSI interrupt number from MSI inner domain
> - */
> advk_writel(pcie, BIT(msi_idx), PCIE_MSI_STATUS_REG);
> - msi_data = advk_readl(pcie, PCIE_MSI_PAYLOAD_REG) & PCIE_MSI_DATA_MASK;
> - virq = irq_find_mapping(pcie->msi_inner_domain, msi_data);
> +
> + virq = irq_find_mapping(pcie->msi_inner_domain, msi_idx);
> if (virq)
> generic_handle_irq(virq);
NAK.
As I have explained before, I want this API dead, and I don't feel
like doing another pass at the whole of the kernel tree to remove
these patterns.
A patch targeting stable is not a mandate for using deprecated
APIs. You can always send another patch for stable versions before
5.14.
M.
--
Without deviation from the norm, progress is not possible.
