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From:   Bharat Kumar Gogada <bharatku@xilinx.com>
To:     "lorenzo.pieralisi@arm.com" <lorenzo.pieralisi@arm.com>
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        "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
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        <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH v2] PCI: xilinx-nwl: Fix Multi MSI data programming
Thread-Topic: [PATCH v2] PCI: xilinx-nwl: Fix Multi MSI data programming
Thread-Index: AQHU2AAQCHDXCwr68kiV0ZLjhatkq6YnqKVQgAGD5wCAAtuSMA==
Date:   Thu, 4 Apr 2019 11:48:24 +0000
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> On Mon, Apr 01, 2019 at 05:00:40PM +0000, Bharat Kumar Gogada wrote:
> > Hi All,
> >
> > Please let me know if anyone has any inputs on this.
> >
> > Regards,
> > Bharat
> > >
> > > The current Multi MSI data programming fails if multiple end points
> > > requesting MSI and multi MSI are connected with switch, i.e the
> > > current multi MSI data being given is not considering the number of
> > > vectors being requested in case of multi MSI.
> > > Due to this if multiple end points are connected and requesting MSI
> > > and multi MSI combination, the multi MSI data is ending up using
> > > wrong MSI data, which might be used by different device.
> > >
> > > Fix Multi MSI data programming with required alignment by using
> > > number of vectors being requested.
>=20
> I still do not understand what you mean I am sorry. An example is worth
> two thousand words, I would start with that as it stands this commit log
> does not provide any information on what you are actually fixing.
>
Hi Lorenzo, Thanks for your time.=20
Yes, will add an example to describe the problem.
=20
Regards,
Bharat
> > > Fixes: ab597d35ef11 ("PCI: xilinx-nwl: Add support for Xilinx NWL
> > > PCIe Host
> > > Controller")
> > > Signed-off-by: Bharat Kumar Gogada
> <bharat.kumar.gogada@xilinx.com>
> > > ---
> > > V2:
> > >  - Added more description of fix
> > > ---
> > >  drivers/pci/controller/pcie-xilinx-nwl.c | 2 +-
> > >  1 file changed, 1 insertion(+), 1 deletion(-)
> > >
> > > diff --git a/drivers/pci/controller/pcie-xilinx-nwl.c
> > > b/drivers/pci/controller/pcie-xilinx-nwl.c
> > > index 81538d7..36669c5 100644
> > > --- a/drivers/pci/controller/pcie-xilinx-nwl.c
> > > +++ b/drivers/pci/controller/pcie-xilinx-nwl.c
> > > @@ -484,7 +484,7 @@ static int nwl_irq_domain_alloc(struct
> > > irq_domain *domain, unsigned int virq,
> > >
> > >  	mutex_lock(&msi->lock);
> > >  	bit =3D bitmap_find_next_zero_area(msi->bitmap, INT_PCI_MSI_NR, 0,
> > > -					 nr_irqs, 0);
> > > +					 nr_irqs, nr_irqs - 1);
> > >  	if (bit >=3D INT_PCI_MSI_NR) {
> > >  		mutex_unlock(&msi->lock);
> > >  		return -ENOSPC;
> > > --
> > > 2.7.4
> >