> -----Original Message-----
> From: David Miller <davem@xxxxxxxxxxxxx>
> Sent: 06 October 2018 03:21
> To: sunil.kovvuri@xxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx; arnd@xxxxxxxx; linux-soc@xxxxxxxxxxxxxxx;
> sgoutham@xxxxxxxxxxx; amakarov@xxxxxxxxxxx; lbartosik@xxxxxxxxxxx
> Subject: [EXT] Re: [PATCH v6 04/15] octeontx2-af: Add mailbox support infra
>
>
> ----------------------------------------------------------------------
> From: sunil.kovvuri@xxxxxxxxx
> Date: Thu, 4 Oct 2018 23:51:47 +0530
>
> > +int otx2_mbox_init(struct otx2_mbox *mbox, void *hwbase, struct
> pci_dev *pdev,
> > + void *reg_base, int direction, int ndevs) {
> > + int devid;
> > + struct otx2_mbox_dev *mdev;
>
> Please order local variable declarations from longest to shortest line.
>
> Please audit your entire series for this problem.
Sure, will fix this and re-submit.
>
> > +int otx2_mbox_busy_poll_for_rsp(struct otx2_mbox *mbox, int devid) {
> > + struct otx2_mbox_dev *mdev = &mbox->dev[devid];
> > + unsigned long timeout = jiffies + 1 * HZ;
> > +
> > + while (!time_after(jiffies, timeout)) {
> > + if (mdev->num_msgs == mdev->msgs_acked)
> > + return 0;
> > + cpu_relax();
> > + }
> > + return -EIO;
> > +}
>
> Probably not a good idea to poll something in the kernel for an entire
> second. Please add a preemption point like a usleep() or similar.
> cpu_relax() does not yield the cpu to the scheduler.
>
> Thank you.
APIs with both modes are added here i.e
otx2_mbox_wait_for_rsp() - which sleeps on every check as you suggested.
This API will be used 99% of the cases.
otx2_mbox_busy_poll_for_rsp() - This API is a busy poll one which is intended to be used in
cases where polling is not allowed. An example would be
' .ndo_set_rx_mode' when netdev driver has to change mode
It frames and sends mailbox message to this AF driver and busy polls
for response.
Thanks,
Sunil.
