Author: marcel
Date: Fri May 29 20:50:41 2015
New Revision: 283754
URL: https://svnweb.freebsd.org/changeset/base/283754
Log:
Do not set d_fwsectors nor d_fwheads. Primarily because the values
tend to be invalid. On a Beaglebone Black, we get 8192 sectors per
track and that causes major breakages.
Differential Revision: D2646
Reviewed by: ian@ imp@
Modified:
head/sys/dev/mmc/mmcsd.c
Modified: head/sys/dev/mmc/mmcsd.c
==============================================================================
--- head/sys/dev/mmc/mmcsd.c Fri May 29 20:22:53 2015 (r283753)
+++ head/sys/dev/mmc/mmcsd.c Fri May 29 20:50:41 2015 (r283754)
@@ -163,33 +163,10 @@ mmcsd_attach(device_t dev)
d->d_sectorsize = mmc_get_sector_size(dev);
d->d_maxsize = mmc_get_max_data(dev) * d->d_sectorsize;
d->d_mediasize = (off_t)mmc_get_media_size(dev) * d->d_sectorsize;
- d->d_stripeoffset = 0;
d->d_stripesize = mmc_get_erase_sector(dev) * d->d_sectorsize;
d->d_unit = device_get_unit(dev);
d->d_flags = DISKFLAG_CANDELETE;
- d->d_delmaxsize = mmc_get_erase_sector(dev) * d->d_sectorsize * 1; /*
conservative */
- /*
- * The d_fw* values are fake. However, layout is aided by making the
- * number of fwsectors equal to the erase sectors from the drive since
- * we set the stripe size equal to that. We set fwheads such that there
- * are ~20 cylinder groups since all values are somewhat arbitrary here
- * and this gives good behavior with ffs without wasting too much
- * space. Sadly, geom_part wants to round partitions to these
- * values. While not bad, in and of itself, the values we present here
- * will almost certainly be different then the values that USB SD
- * adapters use and there's too much variation between brands to just
- * use those values here. Also SD to ATA adapters favor traditional
- * ata sizes, which are different again from the USB adapters (which
- * favor SCSI values). This rounding leads to a loss of up to 5% of the
- * usable space (usually much less, but that's why 20 was selected: to
- * limit this effect at a few percent). gpart needs a way to override
- * this behavior for situations like this, but doesn't provide
- * one. Perhaps this behavior should be tunable as well, but maybe that
- * belongs in the disk layer. These values will be much better than
- * the default ones.
- */
- d->d_fwsectors = mmc_get_erase_sector(dev);
- d->d_fwheads = mmc_get_media_size(dev) / (d->d_fwsectors * 20);
+ d->d_delmaxsize = mmc_get_erase_sector(dev) * d->d_sectorsize;
strlcpy(d->d_ident, mmc_get_card_sn_string(dev), sizeof(d->d_ident));
strlcpy(d->d_descr, mmc_get_card_id_string(dev), sizeof(d->d_descr));
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