Date: Fri, 7 Sep 2018 23:17:09 -0700 From: Mark Millard <marklmi@yahoo.com> To: freebsd-arm <freebsd-arm@freebsd.org> Cc: Emmanuel Vadot <manu@bidouilliste.com>, Marius Strobl <marius@freebsd.org> Subject: An experimental hack that makes head -r338518 boot from e.MMC via an microsd card adapter, in DDR52 mode at that Message-ID: <6D375D5B-34E2-4124-9A32-92C320AD6A54@yahoo.com>
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The following hack demonstrates what is blocking
the use of e.MMC on an adapter on the Pine64+ 2GB
that I can test with (and likely more).
In essence the hack makes the code ignore "Failed
to set VCCQ" for DDR52 and so use the default
VCCQ and keep going.
# svnlite diff /usr/src/sys/dev/mmc/mmc.c =
=
=20
Index: /usr/src/sys/dev/mmc/mmc.c
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--- /usr/src/sys/dev/mmc/mmc.c (revision 338518)
+++ /usr/src/sys/dev/mmc/mmc.c (working copy)
@@ -2226,7 +2226,7 @@
if (mmc_set_vccq(sc, ivar, timing) !=3D =
MMC_ERR_NONE) {
device_printf(dev, "Failed to set VCCQ =
for "
"card at relative address %d\n", =
rca);
- continue;
+ //continue;
}
}
But that does not show what ended up executing instead.
So, giving more context:
if (timing =3D=3D bus_timing_mmc_ddr52) {
/*
* Set EXT_CSD_BUS_WIDTH_n_DDR in =
EXT_CSD_BUS_WIDTH
* (must be done after switching to =
EXT_CSD_HS_TIMING).
*/
if (mmc_set_card_bus_width(sc, ivar, timing) !=3D
MMC_ERR_NONE) {
device_printf(dev, "Card at relative =
address "
"%d failed to set bus width\n", =
rca);
continue;
}
mmcbr_set_bus_width(dev, ivar->bus_width);
mmcbr_update_ios(dev);
if (mmc_set_vccq(sc, ivar, timing) !=3D =
MMC_ERR_NONE) {
device_printf(dev, "Failed to set VCCQ =
for "
"card at relative address %d\n", =
rca);
//continue;
}
}
=20
/* Set clock (must be done before initial tuning). */
mmcbr_set_clock(dev, max_dtr);
mmcbr_update_ios(dev);
. . .
power_class:
if (mmc_set_power_class(sc, ivar) !=3D MMC_ERR_NONE) {
device_printf(dev, "Card at relative address %d =
"
"failed to set power class\n", rca);
}
This is inside the loop:
for (i =3D 0; i < sc->child_count; i++) {
in:
static int
mmc_calculate_clock(struct mmc_softc *sc)
in:
/usr/src/sys/dev/mmc/mmc.c
The result is:
mmc0: setting transfer rate to 52.000MHz (dual data rate timing)
mmc0: Failed to set VCCQ for card at relative address 2
mmcsd0: 125GB <MMCHC DJNB4R 0.7 SN 9F43B2E7 MFG 06/2016 by 21 0x0000> at =
mmc0 52.0MHz/4bit/32768-block
mmcsd0boot0: 4MB partion 1 at mmcsd0
mmcsd0boot1: 4MB partion 2 at mmcsd0
mmcsd0rpmb: 4MB partion 3 at mmcsd0
. . .
It boots to an operating multi-user environment just fine.
(I've not yet done things like buildworld or poudriere bulk.)
As evidence of DDR52 instead of High Speed:
# dd if=3D/dev/mmcsd0 of=3D/dev/null bs=3D1m
^C
811+0 records in
811+0 records out
850395136 bytes transferred in 20.315078 secs (41860294 bytes/sec)
=3D=3D=3D
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)
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