Daisuke Kobayashi (Fujitsu) wrote:
[..]
> I would like to report on some additional findings.
> The process of registering cxl_rcd_groups to struct pci_driver.driver.dev_groups seems
> to not generate a file in sysfs when looking at the contents of the module_pci_driver() macro.
Oh, apologies, and thanks for taking a deeper look. The failure is
because my suggested example led you astray. I suggested this:
diff --git a/drivers/cxl/pci.c b/drivers/cxl/pci.c
index 2ff361e756d6..eec04f103aa8 100644
--- a/drivers/cxl/pci.c
+++ b/drivers/cxl/pci.c
@@ -971,6 +971,7 @@ static struct pci_driver cxl_pci_driver = {
.err_handler = &cxl_error_handlers,
.driver = {
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
+ .dev_groups = cxl_rcd_groups,
},
};
...the correct place to put it is here:
@@ -969,6 +969,7 @@ static struct pci_driver cxl_pci_driver = {
.id_table = cxl_mem_pci_tbl,
.probe = cxl_pci_probe,
.err_handler = &cxl_error_handlers,
+ .dev_groups = cxl_rcd_groups,
.driver = {
.probe_type = PROBE_PREFER_ASYNCHRONOUS,
},
...otherwise __pci_register_driver() will overwrite it. This is a subtle
bug given probe_type is directly initialized in .driver.
> For this feature, I think it would be best to output the values to a directory
> of /sys/bus/pci/devices/<pci-addr>/. To output to this directory, the attribute would
> need to be registered to pci_dev.dev.
> My current understanding is that the best way to do this would be to register the attribute
> with device_add_groups(&pdev->dev, cxl_rcd_groups) on probe and remove the files with
No, the dynamic sysfs registration APIs should be avoided when possible.
The above fix is what you need.
