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Sashiko AI review found 1 potential issue(s) to consider: > - [High] devm mappings for dport BI registers leak on hotplug due to being called outside the dport devres group in cxl_port_add_dport. > -- > > commit a836080fdf13fa334055f7f13a95491b66ef793f > Author: Davidlohr Bueso > > cxl: Add BI register probing and port initialization > > This commit adds register probing for BI Route Table and BI Decoder capability > structures. It introduces helpers to map the BI Decoder of a downstream port > at dport-creation time and a port's own BI capability during port probe. > > > diff --git a/drivers/cxl/port.c b/drivers/cxl/port.c > > index ada51948d52fa..ca8d8c14b7876 100644 > > --- a/drivers/cxl/port.c > > +++ b/drivers/cxl/port.c > > [ ... ] > > > @@ -261,6 +321,17 @@ static struct cxl_dport *cxl_port_add_dport(struct cxl_port *port, > > /* This group was only needed for early exit above */ > > devres_remove_group(&port->dev, no_free_ptr(port_dr_group)); > > > > + if (dev_is_pci(dport_dev)) { > > + switch (pci_pcie_type(to_pci_dev(dport_dev))) { > > + case PCI_EXP_TYPE_ROOT_PORT: > > + case PCI_EXP_TYPE_DOWNSTREAM: > > + cxl_dport_map_bi(dport); > > [Severity: High] > Does this leak devm mappings if the dport is hot-removed? > > Looking at cxl_port_add_dport(), devm_cxl_add_dport_by_dev() creates a > devres group for the dport on the parent port's device. However, > cxl_dport_map_bi() is called after devm_cxl_add_dport_by_dev() returns, > meaning the devres group has already been closed. > > Because cxl_dport_map_bi() calls devm_cxl_iomap_block() against the parent > port device, these devm allocations bypass the dport group and attach > directly to the parent port device. > > If the dport is hot-removed, the dport devres group is released, but the BI > capability mappings appear to be left behind. If the dport is subsequently > re-added, won't devm_request_mem_region() fail with -EBUSY due to the > physical address region conflict, permanently breaking BI capabilities? > Hi Davidlohr, I think sashiko-bot's is right on this part, this part runs after devm_cxl_add_dport_by_dev() has already closed the dport's devres group, so the BI request_mem_region()/ioremap() land on the port's devres list outside that group. On runtime dport removal the group release won't free them, and re-adding the dport then fails the BI region request with -EBUSY. The dport RAS mapping is done inside __devm_cxl_add_dport() while the group is still open for this reason. I would suggest mapping BI the same way which is to move cxl_dport_map_bi() into __devm_cxl_add_dport() next to the RAS setup, and set map->host like RAS does. What do you think ? Best regards, Richard Cheng. > > + break; > > + default: > > + break; > > + } > > + } > > + > > cxl_switch_parse_cdat(dport); > > > > /* New dport added, update the decoder targets */ > > -- > Sashiko AI review · https://sashiko.dev/#/patchset/20260615145529.13848-1-dave@stgolabs.net?part=1 >