On Wed, Mar 11, 2020 at 11:13 PM Douglas Gilbert <dgilbert@xxxxxxxxxxxx> wrote: > > On 2020-03-11 1:08 p.m., Jinpu Wang wrote: > > On Tue, Jan 28, 2020 at 10:43 AM <Deepak.Ukey@xxxxxxxxxxxxx> wrote: > >> > >> > >> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe > >> > >> On 22/01/2020 08:50, Deepak.Ukey@xxxxxxxxxxxxx wrote: > >>> -r--r--r-- 1 root root 4096 Jan 21 12:05 running_disparity_error_count > >>> *** > >>> -r--r--r-- 1 root root 4096 Jan 21 12:05 sas_address > >>> lrwxrwxrwx 1 root root 0 Jan 21 11:45 subsystem -> > >>> ../../../../../../../class/sas_phy > >>> -r--r--r-- 1 root root 4096 Jan 21 12:05 target_port_protocols > >>> -rw-r--r-- 1 root root 4096 Jan 21 11:45 uevent > >>> > >>> Maybe the other stuff provided in the patches are useful, I don't know. > >>> But debugfs seems better for that. > >>> > >>> - 0006-pm80xx-sysfs-attribute-for-number-of-phys > >>> - 0007-pm80xx-IOCTL-functionality-to-get-phy-status gets things like Programmed Link Rate, Negotiated Link Rate, PHY Identifier > >>> - 0008-pm80xx-IOCTL-functionality-to-get-phy-error provides other things like Invalid Dword Error Count, Disparity Error Count > >>> - Thanks for addressing it. We can get this info from /sys/class/sas_phy and /sys/class/sas_port so we will drop these above mentioned three patches from the next - patch series. > >>> > > > >>> > >>> - 0009-pm80xx-IOCTL-functionality-for-GPIO > >>> - 0013-pm80xx-IOCTL-functionality-for-TWI-device > >>> - For the above patches management utility passes command specific information to driver through IOCTL structure, which used by driver to frame the command and - send to FW. We are using the IOCTL interface for the same. Please let us know your thought. > >> > >> So I specifically questioned the SGPIO patch and why it would have an IOCTL, as this function is supported in kernel libsas/SAS transport code as an SMP function. > >>> Thank you for your suggestions. We will make use of function supported in libsas. > > > > So basically you only need IOCTL for GPIO and TWI devices, others can > > implement via libsas interface or from sysfs directly. > > > > I would like to suggest you do send out other changes without the > > IOCTL parts first, and consider again Is it really needed by the user > > to control GPIO and TWI, and if there is other way to do it? > > > > Sorry, I don't have a better suggestion! > > LSI SAS HBAs (LSI now owned by Broadcom) implement an internal ** SMP > target. It can be seen here: > > # ls /dev/bsg > 3:0:0:0 3:0:3:0 8:0:0:0 8:0:0:3 end_device-3:1 expander-3:0 > 3:0:1:0 4:0:0:0 8:0:0:1 8:0:0:4 end_device-3:1:0 expander-3:1 > 3:0:2:0 7:0:0:0 8:0:0:2 end_device-3:0:1 end_device-3:2 sas_host3 > > It is the last device node: "sas_host3". How do I know it is a SMP target? > Because this works: > > # smp_read_gpio /dev/bsg/sas_host3 > Read GPIO register response: > GPIO_CFG[0]: > version: 0 > GPIO enable: 1 > cfg register count: 2 > gp register count: 1 > supported drive count: 16 > > When you work out what LSI are doing with this, perhaps you could write > an article about it and make it publicly available. > It is always a good idea to see how your competitors solve problems :-) This sounds indeed a better solution, thanks for the info, Doug @Deepak Ukey can you check if you guys can also do it this way? Regards, Jack Wang
