Re: [PATCH v3] PCI: aardvark: Fix PCI_EXP_RTCTL register configuration

From: Lorenzo Pieralisi
Date: Tue Aug 06 2019 - 12:28:17 EST


On Fri, Jun 14, 2019 at 12:10:59PM +0200, Remi Pommarel wrote:
> PCI_EXP_RTCTL is used to activate PME interrupt only, so writing into it
> should not modify other interrupts' mask. The ISR mask polarity was also
> inverted, when PCI_EXP_RTCTL_PMEIE is set PCIE_MSG_PM_PME_MASK mask bit
> should actually be cleared.
>
> Fixes: 8a3ebd8de328 ("PCI: aardvark: Implement emulated root PCI bridge config space")
> Signed-off-by: Remi Pommarel <repk@xxxxxxxxxxxx>
> ---
> Changes since v1:
> * Improve code readability
> * Fix mask polarity
> * PME_MASK shift was off by one
> Changes since v2:
> * Modify patch title
> * Change Fixes tag to commit that actually introduces the bug
> ---
> drivers/pci/controller/pci-aardvark.c | 13 +++++++++----
> 1 file changed, 9 insertions(+), 4 deletions(-)

Thomas, are you OK with this patch ?

Thanks,
Lorenzo

> diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
> index 134e0306ff00..f6e55c4597b1 100644
> --- a/drivers/pci/controller/pci-aardvark.c
> +++ b/drivers/pci/controller/pci-aardvark.c
> @@ -415,7 +415,7 @@ advk_pci_bridge_emul_pcie_conf_read(struct pci_bridge_emul *bridge,
>
> case PCI_EXP_RTCTL: {
> u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG);
> - *value = (val & PCIE_MSG_PM_PME_MASK) ? PCI_EXP_RTCTL_PMEIE : 0;
> + *value = (val & PCIE_MSG_PM_PME_MASK) ? 0 : PCI_EXP_RTCTL_PMEIE;
> return PCI_BRIDGE_EMUL_HANDLED;
> }
>
> @@ -451,10 +451,15 @@ advk_pci_bridge_emul_pcie_conf_write(struct pci_bridge_emul *bridge,
> advk_writel(pcie, new, PCIE_CORE_PCIEXP_CAP + reg);
> break;
>
> - case PCI_EXP_RTCTL:
> - new = (new & PCI_EXP_RTCTL_PMEIE) << 3;
> - advk_writel(pcie, new, PCIE_ISR0_MASK_REG);
> + case PCI_EXP_RTCTL: {
> + /* Only mask/unmask PME interrupt */
> + u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG) &
> + ~PCIE_MSG_PM_PME_MASK;
> + if ((new & PCI_EXP_RTCTL_PMEIE) == 0)
> + val |= PCIE_MSG_PM_PME_MASK;
> + advk_writel(pcie, val, PCIE_ISR0_MASK_REG);
> break;
> + }
>
> case PCI_EXP_RTSTA:
> new = (new & PCI_EXP_RTSTA_PME) >> 9;
> --
> 2.20.1
>