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Date:   Tue, 2 Apr 2019 17:08:14 +0100
From:   Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
To:     Bharat Kumar Gogada <bharatku@xilinx.com>
Cc:     "bhelgaas@google.com" <bhelgaas@google.com>,
        "linux-pci@vger.kernel.org" <linux-pci@vger.kernel.org>,
        "linux-arm-kernel@lists.infradead.org" 
        <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
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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.

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.

Lorenzo

> > 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 = bitmap_find_next_zero_area(msi->bitmap, INT_PCI_MSI_NR, 0,
> > -					 nr_irqs, 0);
> > +					 nr_irqs, nr_irqs - 1);
> >  	if (bit >= INT_PCI_MSI_NR) {
> >  		mutex_unlock(&msi->lock);
> >  		return -ENOSPC;
> > --
> > 2.7.4
>