Re: [dpdk-dev] [PATCH 1/3] bus/pci: update device devargs on each rescan

["Gaëtan Rivet" <gaetan.rivet@6wind.com>]

Hi Darek,

On Mon, Nov 05, 2018 at 08:04:45AM +0100, Darek Stojaczyk wrote:
> Bus rescan is done e.g. during the device hotplug,
> where devargs are re-allocated. By not updating the
> rte_device->devargs pointer we potentially make it
> a dangling one, as previous devargs could have been
> (or will be soon) freed.
> 
> Fixes: 55e411b301c3 ("bus/pci: fix resource mapping override")
> Cc: qi.z.zhang@intel.com
> 
> Signed-off-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
> ---
>  drivers/bus/pci/linux/pci.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/bus/pci/linux/pci.c b/drivers/bus/pci/linux/pci.c
> index f87533c5c..f3172960e 100644
> --- a/drivers/bus/pci/linux/pci.c
> +++ b/drivers/bus/pci/linux/pci.c
> @@ -349,10 +349,10 @@ pci_scan_one(const char *dirname, const struct rte_pci_addr *addr)
>  			if (ret < 0) {
>  				rte_pci_insert_device(dev2, dev);
>  			} else { /* already registered */
> +				pci_name_set(dev2);

This is rather unfortunate to call pci_name_set()
to trigger the mapping devargs <-> devices.

pci_devargs_lookup could be made non-static instead,
if that's sufficient. Given that the PCI id matches because the device
is a duplicate (already registered), then the name itself probably does
not need to be updated.

>  				if (!rte_dev_is_probed(&dev2->device)) {
>  					dev2->kdrv = dev->kdrv;
>  					dev2->max_vfs = dev->max_vfs;
> -					pci_name_set(dev2);
>  					memmove(dev2->mem_resource,
>  						dev->mem_resource,
>  						sizeof(dev->mem_resource));
> -- 
> 2.17.1
> 

-- 
Gaëtan Rivet
6WIND