The newbus lock is responsible for protecting newbus internIal structures,
device states and devclass flags. It is necessary to hold it when all
such datas are accessed. For the other operations, softc locking should
ensure enough protection to avoid races.
Newbus lock is automatically held when virtual operations on the device
and bus are invoked when loading the driver or when the suspend/resume
take place. For other 'spourious' operations trying to access/modify
the newbus topology, newbus lock needs to be automatically acquired and
dropped.
For the moment Giant is also acquired in some key point (modules subsystem)
in order to avoid problems before the 8.0 release as module handlers could
make assumptions about it. This Giant locking should go just after
the release happens.
Please keep in mind that the public interface can be expanded in order
to provide more support, if there are really necessities at some point
and also some bugs could arise as long as the patch needs a bit of
further testing.
Bump __FreeBSD_version in order to reflect the newbus lock introduction.
Reviewed by: ed, hps, jhb, imp, mav, scottl
No answer by: ariff, thompsa, yongari
Tested by: pho,
G. Trematerra <giovanni dot trematerra at gmail dot com>,
Brandon Gooch <jamesbrandongooch at gmail dot com>
Sponsored by: Yahoo! Incorporated
Approved by: re (ksmith)
Now it is possible to suspend/resume with inserted and active card.
To reinitialize card on resume and to detect card change while suspended,
implement bus rescan routines. It can also be used by controllers without
card presence detection signals or with multiple cards per slot support.
While there, cleanup msleep() usage. We have no any rights to exit without
"request done" signal from driver as it could lead to modify after free.
sdhci supports up to 65535 blocks transfers, at91_mci - one block.
Enable multiblock operations disabled before to follow at91_mci driver
limitations.
Reviewed by: imp@
Erase operation gives card's logic information about unused areas to help it
implement wear-leveling with lower overhead comparing to usual writing.
Erase is much faster then write and does not depends on data bus speed.
Also as result of hitting in-card write logic optimizations I have measured
up to 50% performance boost on writing undersized blocks into preerased areas.
At the same time there are strict limitations on size and allignment of erase
operations. We can erase only blocks aligned to the erase sector size and
with size multiple of it. Different cards has different erase sector size
which usually varies from 64KB to 4MB. SD cards actually allow to erase
smaller blocks, but it is much more expensive as it is implemented via
read-erase-write sequence and so not sutable for the BIO_DELETE purposes.
Reviewed by: imp@
have in common right now is a memset. This saves a parameter to
these routines, as well as a level of indentation.
o Make mmc_get_bits a little clearer... It really only works on 128-bit
registers right now.
application specific SEND_OP_COND (CMD55 + ACMD41), go ahead and allow
100 tries. This gives a timeout of a second rather than the ~100ms
the old style produces.
I've had one old 16MB SD card which needs the extra time. I've now
had reports from the field that other cards need this too.
Originally done at BSDcan 2007 while waiting to give my embedding
madness minitalk.
SD Simplified specification, as well as other SD and SDIO
implemenations I've examined, suggest this disclaimer may be required.
It is unclear to me exactly what the license would be for, or why it
might be required. Err on the side of caution and include this
disclaimer so anybody deploying this code can judge for themselves. I
have no further unformation about the details.
should be easily adapted to SD 2.0 (aka SDHC), SDIO, MMC and MMCplus
cards. At the present time, there's only one bridge driver for the
ARM9 based Atmel AT91RM9200.
