Re: Comment #135 for bugzilla 237666 : a USB3-handling problem with a investigatory fix for a cortex-a72 context
Mark Millard via freebsd-arm <[email protected]>
| Newsgroups | gmane.os.freebsd.devel.arm |
|---|---|
| Message-ID | <[email protected]> |
On 2020-Sep-19, at 14:18, Mark Millard <marklmi at yahoo.com> wrote:
> On 2020-Sep-19, at 13:54, Mark Millard <marklmi at yahoo.com> wrote:
>
> . . .
>
> The test booted just fine, no "Resetting controller" notices or the
> like. So now I have just:
>
> # svnlite diff /usr/src/sys/dev/usb/controller/xhci.c
> Index: /usr/src/sys/dev/usb/controller/xhci.c
> ===================================================================
> --- /usr/src/sys/dev/usb/controller/xhci.c (revision 363590)
> +++ /usr/src/sys/dev/usb/controller/xhci.c (working copy)
> @@ -431,6 +431,7 @@
>
> phwr->hwr_ring_seg[0].qwEvrsTablePtr = htole64(addr);
> phwr->hwr_ring_seg[0].dwEvrsTableSize = htole32(XHCI_MAX_EVENTS);
> + usb_bus_mem_flush_all(&sc->sc_bus, &xhci_iterate_hw_softc);
>
> DPRINTF("ERDP(0)=0x%016llx\n", (unsigned long long)addr);
>
>
> for the issue. (So my earlier powerpc* SYNC comments are likely junk.)
Comment draft added:
# svnlite diff /usr/src/sys/dev/usb/controller/xhci.c
Index: /usr/src/sys/dev/usb/controller/xhci.c
===================================================================
--- /usr/src/sys/dev/usb/controller/xhci.c (revision 363590)
+++ /usr/src/sys/dev/usb/controller/xhci.c (working copy)
@@ -431,6 +431,17 @@
phwr->hwr_ring_seg[0].qwEvrsTablePtr = htole64(addr);
phwr->hwr_ring_seg[0].dwEvrsTableSize = htole32(XHCI_MAX_EVENTS);
+ /*
+ * For bugzilla 237666:
+ * According to extensible-host-controler-interface-usb-xhci.pdf ,
+ * the later XWRITE4's to XHCI_ERSTBA_LO and _HI lead to the xhci
+ * needing to copy the qwEvrsTablePtr and dwEvrsTableSize
+ * values above at that time (as the xhci initializes its event
+ * ring support). This is before the event ring starts to pay
+ * attention to Run/Stop. Thus, make sure the values are
+ * observable to the xhci before that point.
+ */
+ usb_bus_mem_flush_all(&sc->sc_bus, &xhci_iterate_hw_softc);
DPRINTF("ERDP(0)=0x%016llx\n", (unsigned long long)addr);
===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)
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