[src/trunk]: src/sys/dev/pci PR kern/57035

[rin <rin%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/1e5434f4d4ba
branches:  trunk
changeset: 371247:1e5434f4d4ba
user:      rin <rin%NetBSD.org@localhost>
date:      Sat Oct 01 11:40:08 2022 +0000

description:
PR kern/57035

genfb(4): Fix blank screen after switching to WSDISPLAYIO_MODE_EMUL for
some GPU models like Ice Lake integrated GPU:

- Restore lower words of 64-bit BARs correctly.
- Do not disable expansion ROM if exists.

Thanks ryoon@ for testing!

diffstat:

 sys/dev/pci/genfb_pci.c |  35 ++++++++++++++++++-----------------
 1 files changed, 18 insertions(+), 17 deletions(-)

diffs (75 lines):

diff -r 7cda2e6d3984 -r 1e5434f4d4ba sys/dev/pci/genfb_pci.c
--- a/sys/dev/pci/genfb_pci.c   Sat Oct 01 10:07:55 2022 +0000
+++ b/sys/dev/pci/genfb_pci.c   Sat Oct 01 11:40:08 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: genfb_pci.c,v 1.40 2021/08/07 16:19:14 thorpej Exp $ */
+/*     $NetBSD: genfb_pci.c,v 1.41 2022/10/01 11:40:08 rin Exp $ */
 
 /*-
  * Copyright (c) 2007 Michael Lorenz
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: genfb_pci.c,v 1.40 2021/08/07 16:19:14 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: genfb_pci.c,v 1.41 2022/10/01 11:40:08 rin Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -102,6 +102,7 @@
        struct genfb_ops ops = zero_ops;
        pcireg_t rom;
        int idx, bar, type;
+       bool skip;
 
        pci_aprint_devinfo(pa, NULL);
 
@@ -151,17 +152,23 @@
 
        /* mmap()able bus ranges */
        idx = 0;
-       bar = PCI_MAPREG_START;
-       while (bar <= PCI_MAPREG_ROM) {
+       skip = false;
+       for (bar = PCI_MAPREG_START; bar <= PCI_MAPREG_ROM; bar += 4) {
 
-               sc->sc_bars[(bar - PCI_MAPREG_START) >> 2] = rom =
-                   pci_conf_read(sc->sc_pc, sc->sc_pcitag, bar);
-
-               if ((bar >= PCI_MAPREG_END && bar < PCI_MAPREG_ROM) ||
+               rom = pci_conf_read(sc->sc_pc, sc->sc_pcitag, bar);
+               if ((bar == PCI_MAPREG_ROM) && (rom != 0)) {
+                       rom |= PCI_MAPREG_ROM_ENABLE;
+                       pci_conf_write(sc->sc_pc, sc->sc_pcitag, bar, rom);
+               }
+               sc->sc_bars[(bar - PCI_MAPREG_START) >> 2] = rom;
+               if (skip || (bar >= PCI_MAPREG_END && bar < PCI_MAPREG_ROM) ||
                    pci_mapreg_probe(sc->sc_pc, sc->sc_pcitag, bar, &type)
                    == 0) {
-                       /* skip unimplemented and non-BAR registers */
-                       bar += 4;
+                       /*
+                        * skip unimplemented, non-BAR registers, or
+                        * lower words of 64-bit BARs.
+                        */
+                       skip = false;
                        continue;
                }
                if (PCI_MAPREG_TYPE(type) == PCI_MAPREG_TYPE_MEM || 
@@ -172,15 +179,9 @@
                            &sc->sc_ranges[idx].flags);
                        idx++;
                }
-               if ((bar == PCI_MAPREG_ROM) && (rom != 0)) {
-                       pci_conf_write(sc->sc_pc, sc->sc_pcitag, bar, rom |
-                           PCI_MAPREG_ROM_ENABLE);
-               }
                if (PCI_MAPREG_TYPE(type) == PCI_MAPREG_TYPE_MEM &&
                    PCI_MAPREG_MEM_TYPE(type) == PCI_MAPREG_MEM_TYPE_64BIT)
-                       bar += 8;
-               else
-                       bar += 4;
+                       skip = true;
        }
 
        sc->sc_ranges_used = idx;