[SLOF] [PATCH] xhci: fix missing keys from keyboard

[Dinar Valeev]

Tested-by: Dinar Valeev <dvaleev at suse.com>

On Thu, Apr 28, 2016 at 10:03 PM, Nikunj A Dadhania
<nikunj at linux.vnet.ibm.com> wrote:
> Current handling of the keyboard polling was very slow and
> keys were getting dropped. Done following for fixing this:
>
> * Use multiple buffers per TRB
> * Allocate buffers in xhci according to the number of TRBS.
>
> This reduces the delay of key? processing by getting rid of wait in
> the polling routine.
>
> Reported-by: Dinar Valeev <k0da at opensuse.org>
> Signed-off-by: Nikunj A Dadhania <nikunj at linux.vnet.ibm.com>
> ---
>
> Dinar, can you give this patch a test as well, logic is same,
> some polishing and got rid of magic numbers.
>
>  lib/libusb/usb-xhci.c | 52 +++++++++++++++++++++++++++++++++++++++------------
>  lib/libusb/usb-xhci.h |  2 ++
>  2 files changed, 42 insertions(+), 12 deletions(-)
>
> diff --git a/lib/libusb/usb-xhci.c b/lib/libusb/usb-xhci.c
> index 858cd12..70619c9 100644
> --- a/lib/libusb/usb-xhci.c
> +++ b/lib/libusb/usb-xhci.c
> @@ -238,7 +238,7 @@ static uint64_t xhci_poll_event(struct xhci_hcd *xhcd,
>         flags = le32_to_cpu(event->flags);
>
>         dprintf("Reading from event ptr %p %08x\n", event, flags);
> -       time = SLOF_GetTimer() + USB_TIMEOUT;
> +       time = SLOF_GetTimer() + ((event_type == XHCI_POLL_NO_WAIT)? 0: USB_TIMEOUT);
>
>         while ((flags & TRB_CYCLE_STATE) != xhcd->ering.cycle_state) {
>                 mb();
> @@ -1147,11 +1147,37 @@ static inline void *xhci_get_trb(struct xhci_seg *seg)
>         return (void *)enq;
>  }
>
> +static inline void *xhci_get_trb_deq(struct xhci_seg *seg)
> +{
> +       uint64_t val, deq;
> +       int index;
> +
> +       deq = val = seg->deq;
> +       val = val + XHCI_TRB_SIZE;
> +       index = (deq - (uint64_t)seg->trbs) / XHCI_TRB_SIZE + 1;
> +       dprintf("%s: enq %llx, val %llx %x\n", __func__, enq, val, index);
> +       /* TRBs being a cyclic buffer, here we cycle back to beginning. */
> +       if (index == (seg->size - 1)) {
> +               dprintf("%s: rounding \n", __func__);
> +               seg->deq = (uint64_t)seg->trbs;
> +               mb();
> +       }
> +       else {
> +               seg->deq = val;
> +       }
> +       return (void *)deq;
> +}
> +
>  static uint64_t xhci_get_trb_phys(struct xhci_seg *seg, uint64_t trb)
>  {
>         return seg->trbs_dma + (trb - (uint64_t)seg->trbs);
>  }
>
> +static uint32_t xhci_trb_get_index(struct xhci_seg *seg, struct xhci_transfer_trb *trb)
> +{
> +       return trb - (struct xhci_transfer_trb *)seg->trbs;
> +}
> +
>  static int usb_kb = false;
>  static int xhci_transfer_bulk(struct usb_pipe *pipe, void *td, void *td_phys,
>                         void *data, int datalen)
> @@ -1331,9 +1357,9 @@ static int xhci_get_pipe_intr(struct usb_pipe *pipe,
>                 xhci_init_seg(seg, XHCI_EVENT_TRBS_SIZE, TYPE_BULK);
>         }
>
> -       xpipe->buf = buf;
> -       xpipe->buf_phys = SLOF_dma_map_in(buf, len, false);
> -       xpipe->buflen = len;
> +       xpipe->buflen = pipe->mps * XHCI_INTR_TRBS_SIZE/(sizeof(struct xhci_transfer_trb));
> +       xpipe->buf = SLOF_dma_alloc(xpipe->buflen);
> +       xpipe->buf_phys = SLOF_dma_map_in(xpipe->buf, xpipe->buflen, false);
>
>         ctrl = xhci_get_control_ctx(&xdev->in_ctx);
>         x_epno = xhci_get_epno(pipe);
> @@ -1349,7 +1375,8 @@ static int xhci_get_pipe_intr(struct usb_pipe *pipe,
>         xpipe->seg = seg;
>
>         trb = xhci_get_trb(seg);
> -       fill_normal_trb(trb, (void *)xpipe->buf_phys, pipe->mps);
> +       buf = (char *)(xpipe->buf_phys + xhci_trb_get_index(seg, trb) * pipe->mps);
> +       fill_normal_trb(trb, (void *)buf, pipe->mps);
>         return true;
>  }
>
> @@ -1411,6 +1438,7 @@ static void xhci_put_pipe(struct usb_pipe *pipe)
>         } else if (pipe->type == USB_EP_TYPE_INTR) {
>                 xpipe = xhci_pipe_get_xpipe(pipe);
>                 SLOF_dma_map_out(xpipe->buf_phys, xpipe->buf, xpipe->buflen);
> +               SLOF_dma_free(xpipe->buf, xpipe->buflen);
>                 xpipe->seg = NULL;
>         }
>         if (xhcd->end)
> @@ -1448,26 +1476,26 @@ static int xhci_poll_intr(struct usb_pipe *pipe, uint8_t *data)
>         if (usb_kb == true) {
>                 /* This event was consumed by bulk transfer */
>                 usb_kb = false;
> +               xhci_get_trb_deq(seg);
>                 goto skip_poll;
>         }
> -       buf = xpipe->buf;
> -       memset(buf, 0, 8);
>
> -       mb();
>         /* Ring the doorbell - x_epno */
>         dbr = xhcd->db_regs;
>         write_reg32(&dbr->db[xdev->slot_id], x_epno);
> -       if (!xhci_poll_event(xhcd, 0)) {
> -               printf("poll intr failed\n");
> +       if (!xhci_poll_event(xhcd, XHCI_POLL_NO_WAIT)) {
>                 return 0;
>         }
>         mb();
> +       trb = xhci_get_trb_deq(seg);
> +       buf = xpipe->buf + xhci_trb_get_index(seg, trb) * pipe->mps;
>         memcpy(data, buf, 8);
> +       memset(buf, 0, 8);
>
>  skip_poll:
>         trb = xhci_get_trb(seg);
> -       fill_normal_trb(trb, (void *)xpipe->buf_phys, pipe->mps);
> -       mb();
> +       buf = (uint8_t *)(xpipe->buf_phys + xhci_trb_get_index(seg, trb) * pipe->mps);
> +       fill_normal_trb(trb, (void *)buf, pipe->mps);
>         return ret;
>  }
>
> diff --git a/lib/libusb/usb-xhci.h b/lib/libusb/usb-xhci.h
> index 3fc7e78..8172a37 100644
> --- a/lib/libusb/usb-xhci.h
> +++ b/lib/libusb/usb-xhci.h
> @@ -269,6 +269,8 @@ struct xhci_seg {
>  #define XHCI_INTR_TRBS_SIZE    4096
>  #define XHCI_ERST_NUM_SEGS     1
>
> +#define XHCI_POLL_NO_WAIT      1
> +
>  #define XHCI_MAX_BULK_SIZE    0xF000
>
>  struct xhci_erst_entry {
> --
> 2.5.5
>