On Thu, Jan 07, 2021 at 02:07:08PM +0800, Xu Yilun wrote:
> This driver supports the ethernet retimers (C827) for the Intel PAC
> (Programmable Acceleration Card) N3000, which is a FPGA based Smart NIC.
>
> C827 is an Intel(R) Ethernet serdes transceiver chip that supports
> up to 100G transfer. On Intel PAC N3000 there are 2 C827 chips
> managed by the Intel MAX 10 BMC firmware. They are configured in 4 ports
> 10G/25G retimer mode. Host could query their link states and firmware
> version information via retimer interfaces (Shared registers) on Intel
> MAX 10 BMC. The driver creates sysfs interfaces for users to query these
> information.
Networking people, please look at this sysfs file:
> +What:
> /sys/bus/platform/devices/n3000bmc-retimer.*.auto/link_statusX
> +Date: Jan 2021
> +KernelVersion: 5.12
> +Contact: Xu Yilun <yilun...@intel.com>
> +Description: Read only. Returns the status of each line side link. "1" for
> + link up, "0" for link down.
> + Format: "%u".
as I need your approval to add it because it is not the "normal" way for
link status to be exported to userspace.
One code issue:
> +#define to_link_attr(dev_attr) \
> + container_of(dev_attr, struct link_attr, attr)
> +
> +static ssize_t
> +link_status_show(struct device *dev, struct device_attribute *attr, char
> *buf)
> +{
> + struct m10bmc_retimer *retimer = dev_get_drvdata(dev);
> + struct link_attr *lattr = to_link_attr(attr);
> + unsigned int val;
> + int ret;
> +
> + ret = m10bmc_sys_read(retimer->m10bmc, M10BMC_PKVL_LSTATUS, &val);
> + if (ret)
> + return ret;
> +
> + return sysfs_emit(buf, "%u\n",
> + !!(val & BIT((retimer->id << 2) + lattr->index)));
> +}
> +
> +#define link_status_attr(_index) \
> + static struct link_attr link_attr_status##_index = \
> + { .attr = __ATTR(link_status##_index, 0444, \
> + link_status_show, NULL), \
> + .index = (_index) }
Why is this a "raw" attribute and not a device attribute?
Please just use a normal DEVICE_ATTR_RO() macro to make it simpler and
easier to understand over time, what you are doing here. I can't
determine what is happening with this code now...
thanks,
greg k-h
