Hi Fernando, On 9/6/23 21:52, Fernando Eckhardt Valle wrote: > Newer Thinkpads have a feature called Mac Address Passthrough. > This patch provides a sysfs interface that userspace can use > to get this auxiliary mac address. > > Signed-off-by: Fernando Eckhardt Valle <fevalle@xxxxxx> Thank you for your patch. At a minimum for this patch to be accepted you will need to document the new sysfs interface in: Documentation/admin-guide/laptops/thinkpad-acpi.rst But I wonder if we should export this information to userspace in this way ? The reason why I'm wondering is because mac-address passthrough in case of using e.g. Lenovo Thunderbolt docks is already supported by the kernel by code for this in drivers/net/usb/r8152.c : https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/usb/r8152.c#n1613 So I'm wondering if we really need this, is there a planned userspace API consumer of the new sysfs interface ? Or is this only intended as a way for a user to query this, iow is this purely intended for informational purposes ? Regards, Hans > --- > drivers/platform/x86/thinkpad_acpi.c | 77 ++++++++++++++++++++++++++++ > 1 file changed, 77 insertions(+) > > diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c > index d70c89d32..0b1c36b0d 100644 > --- a/drivers/platform/x86/thinkpad_acpi.c > +++ b/drivers/platform/x86/thinkpad_acpi.c > @@ -10785,6 +10785,78 @@ static struct ibm_struct dprc_driver_data = { > .name = "dprc", > }; > > +/* > + * Auxmac > + * > + * This auxiliary mac address is enabled in the bios through the > + * Mac Address Passthrough feature. In most cases, there are three > + * possibilities: Internal Mac, Second Mac, and disabled. > + * > + */ > + > +#define AUXMAC_LEN 12 > +#define AUXMAC_START 9 > +#define AUXMAC_STRLEN 22 > +static char auxmac[AUXMAC_LEN]; > + > +static int auxmac_init(struct ibm_init_struct *iibm) > +{ > + acpi_status status; > + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; > + union acpi_object *obj; > + > + status = acpi_evaluate_object(NULL, "\\MACA", NULL, &buffer); > + > + if (ACPI_FAILURE(status)) > + return -ENODEV; > + > + obj = (union acpi_object *)buffer.pointer; > + > + if (obj->type != ACPI_TYPE_STRING || obj->string.length != AUXMAC_STRLEN) { > + pr_info("Invalid buffer for mac addr passthrough.\n"); > + goto auxmacinvalid; > + } > + > + if (strncmp(obj->string.pointer + 0x8, "#", 1) != 0 || > + strncmp(obj->string.pointer + 0x15, "#", 1) != 0) { > + pr_info("Invalid header for mac addr passthrough.\n"); > + goto auxmacinvalid; > + } > + > + memcpy(auxmac, obj->string.pointer + AUXMAC_START, AUXMAC_LEN); > + kfree(obj); > + return 0; > + > +auxmacinvalid: > + kfree(obj); > + memcpy(auxmac, "unavailable", 11); > + return 0; > +} > + > +static struct ibm_struct auxmac_data = { > + .name = "auxmac", > +}; > + > +static ssize_t auxmac_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + if (strncmp(auxmac, "XXXXXXXXXXXX", AUXMAC_LEN) == 0) > + memcpy(auxmac, "disabled", 9); > + > + return sysfs_emit(buf, "%s\n", auxmac); > +} > +static DEVICE_ATTR_RO(auxmac); > + > +static struct attribute *auxmac_attributes[] = { > + &dev_attr_auxmac.attr, > + NULL > +}; > + > +static const struct attribute_group auxmac_attr_group = { > + .attrs = auxmac_attributes, > +}; > + > /* --------------------------------------------------------------------- */ > > static struct attribute *tpacpi_driver_attributes[] = { > @@ -10843,6 +10915,7 @@ static const struct attribute_group *tpacpi_groups[] = { > &proxsensor_attr_group, > &kbdlang_attr_group, > &dprc_attr_group, > + &auxmac_attr_group, > NULL, > }; > > @@ -11414,6 +11487,10 @@ static struct ibm_init_struct ibms_init[] __initdata = { > .init = tpacpi_dprc_init, > .data = &dprc_driver_data, > }, > + { > + .init = auxmac_init, > + .data = &auxmac_data, > + }, > }; > > static int __init set_ibm_param(const char *val, const struct kernel_param *kp)
