Author: rpokala Date: Wed Mar 27 21:50:01 2019 New Revision: 345611 URL: https://svnweb.freebsd.org/changeset/base/345611
Log: Teach jedec_dimm(4) to be more forgiving of non-fatal errors. It looks like some DIMMs claim to have a TSOD, but actually don't. Some claim they weren't able to change the SPD page, but they did. Neither of those should be fatal errors. PR: 235944 Submitted by: Greg V <greg@unrelenting.technology> Reported by: Greg V <greg@unrelenting.technology> Reviewed by: cem MFC after: 1 weeks Sponsored by: Panasas Differential Revision: https://reviews.freebsd.org/D19681 Modified: head/sys/dev/jedec_dimm/jedec_dimm.c Modified: head/sys/dev/jedec_dimm/jedec_dimm.c ============================================================================== --- head/sys/dev/jedec_dimm/jedec_dimm.c Wed Mar 27 21:46:45 2019 (r345610) +++ head/sys/dev/jedec_dimm/jedec_dimm.c Wed Mar 27 21:50:01 2019 (r345611) @@ -270,12 +270,16 @@ jedec_dimm_attach(device_t dev) } /* The MSBit of the TSOD-presence byte reports whether or not the TSOD - * is in fact present. If it is, read manufacturer and device info from - * it to confirm that it's a valid TSOD device. It's an error if any of - * those bytes are unreadable; it's not an error if the device is simply - * not known to us (tsod_match == NULL). - * While DDR3 and DDR4 don't explicitly require a TSOD, essentially all - * DDR3 and DDR4 DIMMs include one. + * is in fact present. (While DDR3 and DDR4 don't explicitly require a + * TSOD, essentially all DDR3 and DDR4 DIMMs include one.) But, as + * discussed in [PR 235944], it turns out that some DIMMs claim to have + * a TSOD when they actually don't. (Or maybe the firmware blocks it?) + * <sigh> + * If the SPD data says the TSOD is present, try to read manufacturer + * and device info from it to confirm that it's a valid TSOD device. + * If the data is unreadable, just continue as if the TSOD isn't there. + * If the data was read successfully, see if it is a known TSOD device; + * it's okay if it isn't (tsod_match == NULL). */ rc = smbus_readb(sc->smbus, sc->spd_addr, tsod_present_offset, &byte); if (rc != 0) { @@ -289,12 +293,14 @@ jedec_dimm_attach(device_t dev) if (rc != 0) { device_printf(dev, "failed to read TSOD Manufacturer ID\n"); - goto out; + rc = 0; + goto no_tsod; } rc = jedec_dimm_readw_be(sc, TSOD_REG_DEV_REV, &devid); if (rc != 0) { device_printf(dev, "failed to read TSOD Device ID\n"); - goto out; + rc = 0; + goto no_tsod; } tsod_match = jedec_dimm_tsod_match(vendorid, devid); @@ -309,6 +315,7 @@ jedec_dimm_attach(device_t dev) } } } else { +no_tsod: tsod_match = NULL; tsod_present = false; } @@ -621,9 +628,12 @@ jedec_dimm_dump(struct jedec_dimm_softc *sc, enum dram rc = smbus_writeb(sc->smbus, (JEDEC_DTI_PAGE | JEDEC_LSA_PAGE_SET1), 0, 0); if (rc != 0) { + /* Some SPD devices (or SMBus controllers?) claim the + * page-change command failed when it actually + * succeeded. Log a message but soldier on. + */ device_printf(sc->dev, "unable to change page: %d\n", rc); - goto out; } /* Add 256 to the store location, because we're in the second * page. _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
