21 Jul, 2011

1 commit

• 7937e878f   mmc: documentation of mmc non-blocking request usage and design. ... Browse Code »

  Documentation about the background and the design of mmc non-blocking.
  Host driver guidelines to minimize request preparation overhead.

  Signed-off-by: Per Forlin
  Acked-by: Randy Dunlap
  Signed-off-by: Chris Ball

  Per Forlin

  2011-07-21 22:34:52 +0800  

25 May, 2011

1 commit

• 371a689f6   mmc: MMC boot partitions support. ... Browse Code »

  1

  Allows device MMC boot partitions to be accessed. MMC partitions are
  treated effectively as separate block devices on the same MMC card.

  Signed-off-by: Andrei Warkentin
  Acked-by: Arnd Bergmann
  Signed-off-by: Chris Ball

  Andrei Warkentin

  2011-05-25 09:01:21 +0800  

12 Aug, 2010

1 commit

• dfe86cba7   mmc: add erase, secure erase, trim and secure trim operations ... Browse Code »

  SD/MMC cards tend to support an erase operation. In addition, eMMC v4.4
  cards can support secure erase, trim and secure trim operations that are
  all variants of the basic erase command.

  SD/MMC device attributes "erase_size" and "preferred_erase_size" have been
  added.

  "erase_size" is the minimum size, in bytes, of an erase operation. For
  MMC, "erase_size" is the erase group size reported by the card. Note that
  "erase_size" does not apply to trim or secure trim operations where the
  minimum size is always one 512 byte sector. For SD, "erase_size" is 512
  if the card is block-addressed, 0 otherwise.

  SD/MMC cards can erase an arbitrarily large area up to and
  including the whole card. When erasing a large area it may
  be desirable to do it in smaller chunks for three reasons:

  1. A single erase command will make all other I/O on the card
  wait. This is not a problem if the whole card is being erased, but
  erasing one partition will make I/O for another partition on the
  same card wait for the duration of the erase - which could be a
  several minutes.

  2. To be able to inform the user of erase progress.

  3. The erase timeout becomes too large to be very useful.
  Because the erase timeout contains a margin which is multiplied by
  the size of the erase area, the value can end up being several
  minutes for large areas.

  "erase_size" is not the most efficient unit to erase (especially for SD
  where it is just one sector), hence "preferred_erase_size" provides a good
  chunk size for erasing large areas.

  For MMC, "preferred_erase_size" is the high-capacity erase size if a card
  specifies one, otherwise it is based on the capacity of the card.

  For SD, "preferred_erase_size" is the allocation unit size specified by
  the card.

  "preferred_erase_size" is in bytes.

  Signed-off-by: Adrian Hunter
  Acked-by: Jens Axboe
  Cc: Kyungmin Park
  Cc: Madhusudhan Chikkature
  Cc: Christoph Hellwig
  Cc: Ben Gardiner
  Cc:
  Signed-off-by: Andrew Morton
  Signed-off-by: Linus Torvalds

  Adrian Hunter

  2010-08-12 23:43:30 +0800