On 2011-03-21 13:48, krishna m wrote:
> > Date: Thu, 17 Mar 2011 09:30:37 +0100
> > From: jan.kis...@siemens.com
> > To: gilles.chanteperd...@xenomai.org; krishnamurth...@hotmail.com
> > CC: firstname.lastname@example.org
> > Subject: Re: MSI support in Xenomai
> > On 2011-03-16 14:26, Gilles Chanteperdrix wrote:
> > > krishna m wrote:
> > >> Hi All, I wanted to know if the latest Xenomai [Version
> > >> xenomai-2.5.6] supports MSI interrupts. I am using the adeos Patch
> > >> [version adeos-ipipe-2.6.37-x86-2.9-00] and corresponding Linux
> > >> kernel [version: linux-2.6.37]. I have read in the Xenomai FAQ that
> > >> MSI is not supported by the ipipe patch just wanted to know if the
> > >> latest Xenomai and Ipipe supports MSI.
> > >
> > > No.
> > Strictly spoken, but it works in practice. See
> > http://thread.gmane.org/gmane.linux.real-time.xenomai.users/12135
> > Jan
> > --
> > Siemens AG, Corporate Technology, CT T DE IT 1
> > Corporate Competence Center Embedded Linux
> Hi Jan,
> Thanks for the reply. I got the following info from you post and i had few
> questions related to this post:
> >> - MSI[-X] usage for RTDM (ie. RT) drivers is basically fine as long as
> avoid enabling/disabling from RT context (also used for quite a while here,
> known issues under this restriction)
> my question is are you mentioninig here that i must not be doing
> pci_enable_msi() and pci_disable_msi() inside the RTDM driver ? if not then
> where should these calls be done ?
pci_enable/disable_msi are initialization services that only need to be
executed over Linux context - also in RTDM drivers.
> Right now i have ported my standerd linux driver for the PCIe card to RTDM
> drvier. This driver uses MSI. I am not enabeling or disabling MSI or IRQ any
> where in the driver while processing [i.e. in ISR or read/write]. I am
> MSI in the PCI Probe and disabeling it in the PCI remove functions. The
> i am facing is as soon as i get the First MSI interrupt the kernel oops and i
> get the following dump:
> |Mar 21 21:08:34 barch kernel: BUG: unable to handle kernel paging request at
> Mar 21 21:08:34 barch kernel: Oops: 0000 [#1] PREEMPT SMP
We would need the full backtrace to have at least a chance to help.
> [note: The normal linux driver works with out any problem].
> Please let me know your thoughts. Also is there an example PCIe RTDM driver
> using MSI that i can refer to understand more about this topic ?
Check RTnet's IGB driver. It works with MSI-X interrupts on x86.
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux
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