Re: [PATCH v2 3/5] PCI: iproc: Disable MSI parsing in certain PAXC blocks

[Ray Jui]

On 6/12/2018 1:29 AM, poza@xxxxxxxxxxxxxx wrote:
> On 2018-06-12 05:51, Ray Jui wrote:
> > The internal MSI parsing logic in certain revisions of PAXC root
> > complexes does not work properly and can casue corruptions on the
> > writes. They need to be disabled
> >
> > Signed-off-by: Ray Jui <ray.jui@xxxxxxxxxxxx>
> > Reviewed-by: Scott Branden <scott.branden@xxxxxxxxxxxx>
> > ---
> > Âdrivers/pci/host/pcie-iproc.c | 34 ++++++++++++++++++++++++++++++++--
> > Â1 file changed, 32 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/pci/host/pcie-iproc.c 
> > b/drivers/pci/host/pcie-iproc.c
> > index 680f6b1..0804aa2 100644
> > --- a/drivers/pci/host/pcie-iproc.c
> > +++ b/drivers/pci/host/pcie-iproc.c
> > @@ -1197,10 +1197,22 @@ static int iproc_pcie_paxb_v2_msi_steer(struct
> > iproc_pcie *pcie, u64 msi_addr)
> > ÂÂÂÂ return ret;
> > Â}
> >
> > -static void iproc_pcie_paxc_v2_msi_steer(struct iproc_pcie *pcie, u64 
> > msi_addr)
> > +static void iproc_pcie_paxc_v2_msi_steer(struct iproc_pcie *pcie, u64 
> > msi_addr,
> > +ÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂÂ bool enable)
> > Â{
> > ÂÂÂÂ u32 val;
> >
> > +ÂÂÂ if (!enable) {
> > +ÂÂÂÂÂÂÂ /*
> > +ÂÂÂÂÂÂÂÂ * Disable PAXC MSI steering. All write transfers will be
> > +ÂÂÂÂÂÂÂÂ * treated as non-MSI transfers
> > +ÂÂÂÂÂÂÂÂ */
> > +ÂÂÂÂÂÂÂ val = iproc_pcie_read_reg(pcie, IPROC_PCIE_MSI_EN_CFG);
> > +ÂÂÂÂÂÂÂ val &= ~MSI_ENABLE_CFG;
> > +ÂÂÂÂÂÂÂ iproc_pcie_write_reg(pcie, IPROC_PCIE_MSI_EN_CFG, val);
> > +ÂÂÂÂÂÂÂ return;
> can be dropped.


No it cannot be dropped. Please review the code carefully.