[v2] pci/linux: copy new id for inserted device
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Commit Message
When a device is inserted into an existing BDF slot
that has not been probed, we must overwrite the old
PCI ID with the ID of the new function. Otherwise
we may not probe the function with the correct driver,
if at all.
Signed-off-by: Jim Harris <james.r.harris@intel.com>
---
drivers/bus/pci/linux/pci.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
Comments
Hi Jim,
Sorry I see nobody reviewed your patch.
Jim Harris <james.r.harris@intel.com> wrote:
> + memcpy(&dev2->id, &dev->id, sizeof(dev2->id));
[...]
> + memcmp(&dev2->id, &dev->id, sizeof(dev2->id)))
Why using memcpy and memcmp instead of simple assignment and comparison?
On 10/7/20, 8:06 AM, "Thomas Monjalon" <thomas@monjalon.net> wrote:
Hi Jim,
Sorry I see nobody reviewed your patch.
Jim Harris <james.r.harris@intel.com> wrote:
> + memcpy(&dev2->id, &dev->id, sizeof(dev2->id));
[...]
> + memcmp(&dev2->id, &dev->id, sizeof(dev2->id)))
Why using memcpy and memcmp instead of simple assignment and comparison?
Direct assignment and comparison would work too. I did see some similar cases though using memcpy for rte_pci_addr (which is similar to rte_pci_id) in linux/pci_uio.c and linux/pci_vfio.c. It wasn't clear to me if direct assignment/comparison for structures was the norm for DPDK.
I'm happy to send a v2 with a direct assignment/comparison though if that is preferred.
-Jim
12/10/2020 22:58, Harris, James R:
>
> On 10/7/20, 8:06 AM, "Thomas Monjalon" <thomas@monjalon.net> wrote:
>
> Hi Jim,
>
> Sorry I see nobody reviewed your patch.
>
> Jim Harris <james.r.harris@intel.com> wrote:
> > + memcpy(&dev2->id, &dev->id, sizeof(dev2->id));
> [...]
> > + memcmp(&dev2->id, &dev->id, sizeof(dev2->id)))
>
> Why using memcpy and memcmp instead of simple assignment and comparison?
>
> Direct assignment and comparison would work too. I did see some similar cases though using memcpy for rte_pci_addr (which is similar to rte_pci_id) in linux/pci_uio.c and linux/pci_vfio.c. It wasn't clear to me if direct assignment/comparison for structures was the norm for DPDK.
>
> I'm happy to send a v2 with a direct assignment/comparison though if that is preferred.
Yes please, direct assignment is preferred.
Thanks
@@ -352,6 +352,7 @@ pci_scan_one(const char *dirname, const struct rte_pci_addr *addr)
if (!rte_dev_is_probed(&dev2->device)) {
dev2->kdrv = dev->kdrv;
dev2->max_vfs = dev->max_vfs;
+ memcpy(&dev2->id, &dev->id, sizeof(dev2->id));
pci_name_set(dev2);
memmove(dev2->mem_resource,
dev->mem_resource,
@@ -365,7 +366,8 @@ pci_scan_one(const char *dirname, const struct rte_pci_addr *addr)
* need to do anything here unless...
**/
if (dev2->kdrv != dev->kdrv ||
- dev2->max_vfs != dev->max_vfs)
+ dev2->max_vfs != dev->max_vfs ||
+ memcmp(&dev2->id, &dev->id, sizeof(dev2->id)))
/*
* This should not happens.
* But it is still possible if