Re: Assign BAR address for pci device after hotplug

[divakar <divakar.chitturi@hpe.com>]

Hi ,

The modified probe function was the one with the pci_reassign_resource 
function. 

modified_my_driver_probe:
static int my_probe(struct pci_dev *pdev, const struct pci_device_id 
*id)
{
 
        /* Enable hotplug support
           TODO: Check if this is right way to do it */
        if( pci_resource_start (pdev,0) <= 0) {
                ret = pci_assign_resource(pdev,0);
                if( 0 > ret) {
                        dev_err(&pdev->dev, " Failed to assign resource 
\n");
                        return ret;
                }
        }

        ret = pci_enable_device(pdev);

}

Thanks for your comments on the hardware. I hope my previous message 
with the output log snippets came through. My observation of the events 
happening seem to suggest there is a hotplug controller as i can see the 
difference between with and without enabling "pciehp". Also 
pci_resource_start in the probe function of the endpoint device driver 
seem to work. Hence my persistence in understanding the behavior. 

Thanks 


On Tuesday, August 09, 2016 02:49:39 AM Greg KH wrote:
> On Mon, Aug 08, 2016 at 05:32:42PM -0700, divakar wrote:
> > Hi Greg,
> > 
> > Thanks for your comments. I managed to install a client which will
> > do
> > the auto format. Hopefully this is better than before. Please find
> > my
> > responses inline. Also added extra questions and information about
> > the setup.
> > 
> > Questions:
> > 1. Since the modified_my_driver_probe is working, is that the
> > recommended way of doing it? I couldn't find any sample drivers
> > using it. So wanted your guidance
> 
> I dont understand, what "modified" probe function?
> 
> > 2. There is no hotplug controller as far is know off in the setup (
> > assuming native x86 soc has root port which has inbuilt hp
> > controller
> > and pcieport driver takes care of it). Am i missing something?
> 
> Then your hardware does not support PCI hotplug, so I don't recommend
> trying to use it.
> 
> Seriously, this is a hardware and BIOS requirement to support this, if
> you don't have that hardware, you can't really work around it in the
> kernel.  Go buy some real hardware for this please.
> 
> > 3. When card 2 is inserted there is no hotplug event. Not sure why.
> 
> Why would there be?  You don't have hardware that notices this.
> 
> good luck,
> 
> greg k-h