From: Pali Rohár pali@kernel.org
[ Upstream commit 805dfc18dd3d4dd97a987d4406593b5a225b1253 ]
In advk_pcie_handle_msi() the authors expect that when bit i in the W1C register PCIE_MSI_STATUS_REG is cleared, the PCIE_MSI_PAYLOAD_REG is updated to contain the MSI number corresponding to index i.
Experiments show that this is not so, and instead PCIE_MSI_PAYLOAD_REG always contains the number of the last received MSI, overall.
Do not read PCIE_MSI_PAYLOAD_REG register for determining MSI interrupt number. Since Aardvark already forbids more than 32 interrupts and uses own allocated hwirq numbers, the msi_idx already corresponds to the received MSI number.
Link: https://lore.kernel.org/r/20220110015018.26359-3-kabel@kernel.org Fixes: 8c39d710363c ("PCI: aardvark: Add Aardvark PCI host controller driver") Signed-off-by: Pali Rohár pali@kernel.org Signed-off-by: Marek Behún kabel@kernel.org Signed-off-by: Lorenzo Pieralisi lorenzo.pieralisi@arm.com Signed-off-by: Marek Behún kabel@kernel.org --- As explained in https://lore.kernel.org/stable/20220503205434.25275-2-kabel@kernel.org/ for 4.14, this needs to be applied ASAP to stable, since another commit was put into stable that breaks this driver.
Thx :) --- drivers/pci/controller/pci-aardvark.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-)
diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c index d43e93eb2fed..7219ca39aa90 100644 --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -1372,7 +1372,7 @@ 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); msi_val = advk_readl(pcie, PCIE_MSI_STATUS_REG); @@ -1382,13 +1382,9 @@ 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 - */ advk_writel(pcie, BIT(msi_idx), PCIE_MSI_STATUS_REG); - msi_data = advk_readl(pcie, PCIE_MSI_PAYLOAD_REG) & PCIE_MSI_DATA_MASK; - generic_handle_irq(msi_data); + virq = irq_find_mapping(pcie->msi_inner_domain, msi_idx); + generic_handle_irq(virq); }
advk_writel(pcie, PCIE_ISR0_MSI_INT_PENDING,