Date: Tue, 13 May 2014 10:03:57 -0400 (EDT) From: Keith White <kwhite@site.uottawa.ca> To: Ian Lepore <ian@freebsd.org> Cc: freebsd-arm <freebsd-arm@freebsd.org> Subject: Re: Patch to make BBB properly boot from eMMC every time Message-ID: <20140513100155.M27352@admin16.site.uottawa.ca> In-Reply-To: <1399987808.56626.2.camel@revolution.hippie.lan> References: <5371E1F3.6080002@hot.ee> <1399987808.56626.2.camel@revolution.hippie.lan>
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On Tue, 13 May 2014, Ian Lepore wrote: > On Tue, 2014-05-13 at 12:12 +0300, Sulev-Madis Silber (ketas) wrote: >> On my BBB, I need following patch to boot from eMMC 100% of cases. >> Without that, device is detected with 1 / 4 bit bus (it's actually 8 >> bit) or not at all (then boot fails). >> >> Actually, that code looks like weird way to implement sleep(), or at >> least it has such (side) effect. >> >> Actually ian@ made that patch, and was confused about results. >> >> >> ------------------------------------------------------------------------- >> Index: sys/dev/mmc/mmc.c >> =================================================================== >> --- sys/dev/mmc/mmc.c (revision 264141) >> +++ sys/dev/mmc/mmc.c (working copy) >> @@ -769,8 +769,10 @@ mmc_test_bus_width(struct mmc_softc *sc) >> data.data = p8; >> data.len = 8; >> data.flags = MMC_DATA_WRITE; >> - mmc_wait_for_cmd(sc, &cmd, 0); >> - >> + err = mmc_wait_for_cmd(sc, &cmd, 0); >> + if (err != 0) >> + device_printf(sc->dev, "BUSTEST_W err %d\n", err); >> + >> memset(&cmd, 0, sizeof(cmd)); >> memset(&data, 0, sizeof(data)); >> cmd.opcode = MMC_BUSTEST_R; >> @@ -782,7 +784,12 @@ mmc_test_bus_width(struct mmc_softc *sc) >> data.len = 8; >> data.flags = MMC_DATA_READ; >> err = mmc_wait_for_cmd(sc, &cmd, 0); >> - >> + if (err != 0) >> + device_printf(sc->dev, "BUSTEST_R err %d\n", err); >> + >> + device_printf(sc->dev, "read %02x %02x %02x %02x %02x >> %02x %02x %02x\n", >> + buf[0], buf[1], buf[2], buf[3], buf[4], buf[5], >> buf[6], buf[7]); >> + >> mmcbr_set_bus_width(sc->dev, bus_width_1); >> mmcbr_update_ios(sc->dev); >> ------------------------------------------------------------------------- > > Confused about the cause of the results, yes. I think the printf I had > you add to help me figure out the problem just changed the timing of the > retry to make it work on the second try, but I have no idea why. > > Does anybody else with a BBB see the device randomly boot up as 1 or 4 > or 8 bits, changing from one boot to the next? The bits are reported in > the mmcsd0 line: > > mmcsd0: 8GB <SDHC SA08G 0.4 SN 2630755555 MFG 10/2009 by 2 TM> at mmc0 > 50.0MHz/4bit/65535-block > > That's from a wandboard, but a BBB eMMC should always be 8 bits. > > -- Ian > > > _______________________________________________ > freebsd-arm@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-arm > To unsubscribe, send any mail to "freebsd-arm-unsubscribe@freebsd.org" Yes, I have the same problem with a BBB. The above patch appears to workaround it. ...keith -- Keith White, genie.uottawa.ca engineering.uottawa.ca kwhite@uottawa.ca [+1 613 562 5800 x6681]
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