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On 9/26/23 3:23 PM, Bjorn Helgaas wrote: > On Mon, Sep 25, 2023 at 03:01:25PM -0500, Ben Cheatham wrote: >> Add cxl_rcrb_addr to the dport_dev (normally represented by a pcie >> device) for CXL RCH root ports. The file will print the RCRB base >> MMIO address of the root port when read and will be used by >> users looking to inject CXL EINJ error types for RCH hosts. > > I guess this is talking about a sysfs file? If so, maybe mention that > explicitly in the subject and commit log. > > I don't know how you decided to capitalize CXL initialisms and not > "pcie", but I usually use "PCIe". > Sorry about that, it's a typo. I should've written PCIE/PCIe. >> +static struct cxl_port *cxl_root; >> + >> +void set_cxl_root(struct cxl_port *root_port) >> +{ >> + cxl_root = root_port; >> +} > > Is there always at most one cxl_root? Seems worth a one-line comment > at the static data item, since in the world of devices, data is > usually in a per-device struct, not in a single static item. > I thought that the root was a singleton, but per Dan's comment it seems that isn't the case. >> @@ -1021,6 +1074,11 @@ __devm_cxl_add_dport(struct cxl_port *port, struct device *dport_dev, >> if (rc) >> return ERR_PTR(rc); >> >> + rc = sysfs_create_group(&dport_dev->kobj, &cxl_rcrb_addr_group); >> + if (rc) >> + dev_dbg(dport_dev, "Couldn't create cxl_rcrb_addr group: %d\n", >> + rc); > > Is there any way to create this with an attribute group that the sysfs > infrastructure adds automatically? I'm not suggesting you have a race > condition here, but using the sysfs infrastructure avoids a lot of > potential problems. > I would need to look into it more. I did it this way because I wasn't sure there was a way to set it up statically since the dport_dev can match a couple of different device types. After looking at Dan's comments I will probably move away from making this file altogether and move the functionality under sysfs/debug/cxl. > Bjorn