Re: [PATCH] PCI: Enable ATS at the device state restore

[Jesse Barnes]

No looks fine, just applied to my linux-next branch.  Thanks.

Jesse

On Tue, 20 Dec 2011 18:15:42 +0800
"Hao, Xudong" <xudong.hao@xxxxxxxxx> wrote:

> Hi, Jesse
> Do you have any comments for this fix patch?
> 
> Thanks,
> -Xudong
> 
> > -----Original Message-----
> > From: Hao, Xudong
> > Sent: Saturday, December 17, 2011 9:25 PM
> > To: 'jbarnes@xxxxxxxxxxxxxxxx'; 'linux-pci@xxxxxxxxxxxxxxx'
> > Cc: linux-kernel@xxxxxxxxxxxxxxx; kvm@xxxxxxxxxxxxxxx; Zhang, Xiantao
> > Subject: [PATCH] PCI: Enable ATS at the device state restore
> > 
> > When system go to S3 or S4 sleep and then return, some register of PCI device
> > does not be restored correctly, such as ATS capability. The same problem
> > happen on pci reset function.
> > 
> > This patch enables ATS at the device state restore if PCI device has ATS
> > capability.
> > 
> > Signed-off-by: Xudong Hao <xudong.hao@xxxxxxxxx>
> > Signed-off-by: Xiantao Zhang <xiantao.zhang@xxxxxxxxx>
> > ---
> >  drivers/pci/ats.c |   17 +++++++++++++++++
> >  drivers/pci/pci.c |    1 +
> >  drivers/pci/pci.h |    8 ++++++++
> >  3 files changed, 26 insertions(+), 0 deletions(-)
> > 
> > diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c index 7ec56fb..a6c2b35 100644
> > --- a/drivers/pci/ats.c
> > +++ b/drivers/pci/ats.c
> > @@ -127,6 +127,23 @@ void pci_disable_ats(struct pci_dev *dev)  }
> > EXPORT_SYMBOL_GPL(pci_disable_ats);
> > 
> > +void pci_restore_ats_state(struct pci_dev *dev) {
> > +	u16 ctrl;
> > +
> > +	if (!pci_ats_enabled(dev))
> > +		return;
> > +	if (!pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ATS))
> > +		BUG();
> > +
> > +	ctrl = PCI_ATS_CTRL_ENABLE;
> > +	if (!dev->is_virtfn)
> > +		ctrl |= PCI_ATS_CTRL_STU(dev->ats->stu - PCI_ATS_MIN_STU);
> > +
> > +	pci_write_config_word(dev, dev->ats->pos + PCI_ATS_CTRL, ctrl); }
> > +EXPORT_SYMBOL_GPL(pci_restore_ats_state);
> > +
> >  /**
> >   * pci_ats_queue_depth - query the ATS Invalidate Queue Depth
> >   * @dev: the PCI device
> > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c index 6f45a73..6dafc1d 100644
> > --- a/drivers/pci/pci.c
> > +++ b/drivers/pci/pci.c
> > @@ -956,6 +956,7 @@ void pci_restore_state(struct pci_dev *dev)
> > 
> >  	/* PCI Express register must be restored first */
> >  	pci_restore_pcie_state(dev);
> > +	pci_restore_ats_state(dev);
> > 
> >  	/*
> >  	 * The Base Address register should be programmed before the command
> > diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h index b74084e..a4f3140 100644
> > --- a/drivers/pci/pci.h
> > +++ b/drivers/pci/pci.h
> > @@ -249,6 +249,14 @@ struct pci_sriov {
> >  	u8 __iomem *mstate;	/* VF Migration State Array */
> >  };
> > 
> > +#ifdef CONFIG_PCI_ATS
> > +extern void pci_restore_ats_state(struct pci_dev *dev); #else static
> > +inline void pci_restore_ats_state(struct pci_dev *dev) { } #endif /*
> > +CONFIG_PCI_ATS */
> > +
> >  #ifdef CONFIG_PCI_IOV
> >  extern int pci_iov_init(struct pci_dev *dev);  extern void
> > pci_iov_release(struct pci_dev *dev);
>

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