2019-05-22 21:27:35

by Remi Pommarel

[permalink] [raw]
Subject: [PATCH] PCI: aardvark: Fix PCI_EXP_RTCTL conf register writing

PCI_EXP_RTCTL is used to activate PME interrupt only, so writing into it
should not modify other interrupts' mask (such as ISR0).

Fixes: 6302bf3ef78d ("PCI: Init PCIe feature bits for managed host bridge alloc")
Signed-off-by: Remi Pommarel <[email protected]>
---
Please note that I will unlikely be able to answer any comments from May
24th to June 10th.
---
drivers/pci/controller/pci-aardvark.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
index 134e0306ff00..27102d3b4f9c 100644
--- a/drivers/pci/controller/pci-aardvark.c
+++ b/drivers/pci/controller/pci-aardvark.c
@@ -451,10 +451,14 @@ 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;
+ val |= (new & PCI_EXP_RTCTL_PMEIE) << 3;
+ advk_writel(pcie, val, PCIE_ISR0_MASK_REG);
break;
+ }

case PCI_EXP_RTSTA:
new = (new & PCI_EXP_RTSTA_PME) >> 9;
--
2.20.1


2019-06-13 16:15:42

by Lorenzo Pieralisi

[permalink] [raw]
Subject: Re: [PATCH] PCI: aardvark: Fix PCI_EXP_RTCTL conf register writing

On Wed, May 22, 2019 at 11:33:49PM +0200, Remi Pommarel wrote:
> PCI_EXP_RTCTL is used to activate PME interrupt only, so writing into it
> should not modify other interrupts' mask (such as ISR0).
>
> Fixes: 6302bf3ef78d ("PCI: Init PCIe feature bits for managed host bridge alloc")
> Signed-off-by: Remi Pommarel <[email protected]>
> ---
> Please note that I will unlikely be able to answer any comments from May
> 24th to June 10th.
> ---
> drivers/pci/controller/pci-aardvark.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
> index 134e0306ff00..27102d3b4f9c 100644
> --- a/drivers/pci/controller/pci-aardvark.c
> +++ b/drivers/pci/controller/pci-aardvark.c
> @@ -451,10 +451,14 @@ 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;
> + val |= (new & PCI_EXP_RTCTL_PMEIE) << 3;

I know you have not introduced this code but maybe we can
take an opportunity to clarify it (that << 3 shift obfuscates
a bit):

u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG) &
~PCIE_MSG_PM_PME_MASK;

if (new & PCI_EXP_RTCTL_PMEIE)
val |= PCIE_MSG_PM_PME_MASK;

advk_writel(pcie, val, PCIE_ISR0_MASK_REG);
break;

Or I am not reading the code correctly ?

Regardless, I need Thomas' ACK to proceed.

Lorenzo

> + advk_writel(pcie, val, PCIE_ISR0_MASK_REG);
> break;
> + }
>
> case PCI_EXP_RTSTA:
> new = (new & PCI_EXP_RTSTA_PME) >> 9;
> --
> 2.20.1
>

2019-06-13 21:57:53

by Remi Pommarel

[permalink] [raw]
Subject: Re: [PATCH] PCI: aardvark: Fix PCI_EXP_RTCTL conf register writing

On Thu, Jun 13, 2019 at 05:14:41PM +0100, Lorenzo Pieralisi wrote:
> On Wed, May 22, 2019 at 11:33:49PM +0200, Remi Pommarel wrote:
> > PCI_EXP_RTCTL is used to activate PME interrupt only, so writing into it
> > should not modify other interrupts' mask (such as ISR0).
> >
> > Fixes: 6302bf3ef78d ("PCI: Init PCIe feature bits for managed host bridge alloc")
> > Signed-off-by: Remi Pommarel <[email protected]>
> > ---
> > Please note that I will unlikely be able to answer any comments from May
> > 24th to June 10th.
> > ---
> > drivers/pci/controller/pci-aardvark.c | 10 +++++++---
> > 1 file changed, 7 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c
> > index 134e0306ff00..27102d3b4f9c 100644
> > --- a/drivers/pci/controller/pci-aardvark.c
> > +++ b/drivers/pci/controller/pci-aardvark.c
> > @@ -451,10 +451,14 @@ 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;
> > + val |= (new & PCI_EXP_RTCTL_PMEIE) << 3;
>
> I know you have not introduced this code but maybe we can
> take an opportunity to clarify it (that << 3 shift obfuscates
> a bit):
>
> u32 val = advk_readl(pcie, PCIE_ISR0_MASK_REG) &
> ~PCIE_MSG_PM_PME_MASK;
>
> if (new & PCI_EXP_RTCTL_PMEIE)
> val |= PCIE_MSG_PM_PME_MASK;
>
> advk_writel(pcie, val, PCIE_ISR0_MASK_REG);
> break;
>
> Or I am not reading the code correctly ?

Sure, that clarifies the code at the point where I realize that the
"<< 3" from the original code was off by one and the mask polarity was
inverted. So I'll fix all that in the v2.

Thanks.

--
Remi