Re: [RFC] disable PCIE 'Enable No Snoop' bit by default

2007-09-10 Thread Shaohua Li
On Mon, 2007-09-10 at 23:15 -0700, Greg KH wrote: > On Tue, Sep 11, 2007 at 09:29:43AM +0800, Shaohua Li wrote: > > On Sun, 2007-09-09 at 09:43 -0700, Greg KH wrote: > > > On Thu, Sep 06, 2007 at 05:40:38AM -0700, David Miller wrote: > > > > From: Matthew Wilcox <[EMAIL PROTECTED]> > > > > Date: Th

Re: [RFC] disable PCIE 'Enable No Snoop' bit by default

2007-09-10 Thread Greg KH
On Tue, Sep 11, 2007 at 09:29:43AM +0800, Shaohua Li wrote: > On Sun, 2007-09-09 at 09:43 -0700, Greg KH wrote: > > On Thu, Sep 06, 2007 at 05:40:38AM -0700, David Miller wrote: > > > From: Matthew Wilcox <[EMAIL PROTECTED]> > > > Date: Thu, 6 Sep 2007 05:57:31 -0600 > > > > > > > I'm not sure you

Re: [RFC] disable PCIE 'Enable No Snoop' bit by default

2007-09-10 Thread Shaohua Li
On Sun, 2007-09-09 at 09:43 -0700, Greg KH wrote: > On Thu, Sep 06, 2007 at 05:40:38AM -0700, David Miller wrote: > > From: Matthew Wilcox <[EMAIL PROTECTED]> > > Date: Thu, 6 Sep 2007 05:57:31 -0600 > > > > > I'm not sure your analysis is correct. Here's what my draft copy of > > > the pcie 2.0

Re: [RFC] disable PCIE 'Enable No Snoop' bit by default

2007-09-09 Thread Greg KH
On Thu, Sep 06, 2007 at 05:40:38AM -0700, David Miller wrote: > From: Matthew Wilcox <[EMAIL PROTECTED]> > Date: Thu, 6 Sep 2007 05:57:31 -0600 > > > I'm not sure your analysis is correct. Here's what my draft copy of > > the pcie 2.0 spec says: > > > > Enble No Snoop ? If this bit is Set, the

Re: [RFC] disable PCIE 'Enable No Snoop' bit by default

2007-09-06 Thread Shaohua Li
On Thu, 2007-09-06 at 05:57 -0600, Matthew Wilcox wrote: > On Thu, Sep 06, 2007 at 01:35:08PM +0800, Shaohua Li wrote: > > PCIE 'Enable No Snoop' bit is set by default per PCIE spec, but OS > > assumes PCI DMA is snooped, which is legacy PCI device does. Enabling no > > snoop might cause potential

Re: [RFC] disable PCIE 'Enable No Snoop' bit by default

2007-09-06 Thread David Miller
From: Matthew Wilcox <[EMAIL PROTECTED]> Date: Thu, 6 Sep 2007 05:57:31 -0600 > I'm not sure your analysis is correct. Here's what my draft copy of > the pcie 2.0 spec says: > > Enble No Snoop ­ If this bit is Set, the Function is permitted to > Set the No Snoop bit in the Requester Attribut

Re: [RFC] disable PCIE 'Enable No Snoop' bit by default

2007-09-06 Thread Matthew Wilcox
On Thu, Sep 06, 2007 at 01:35:08PM +0800, Shaohua Li wrote: > PCIE 'Enable No Snoop' bit is set by default per PCIE spec, but OS > assumes PCI DMA is snooped, which is legacy PCI device does. Enabling no > snoop might cause potential DMA issues. This patch disables it, if a > driver can work with n