diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/Documentation/mmc/mmc-dev-attrs.txt | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/Documentation/mmc/mmc-dev-attrs.txt')
-rw-r--r-- | kernel/Documentation/mmc/mmc-dev-attrs.txt | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/kernel/Documentation/mmc/mmc-dev-attrs.txt b/kernel/Documentation/mmc/mmc-dev-attrs.txt new file mode 100644 index 000000000..189bab092 --- /dev/null +++ b/kernel/Documentation/mmc/mmc-dev-attrs.txt @@ -0,0 +1,84 @@ +SD and MMC Block Device Attributes +================================== + +These attributes are defined for the block devices associated with the +SD or MMC device. + +The following attributes are read/write. + + force_ro Enforce read-only access even if write protect switch is off. + +SD and MMC Device Attributes +============================ + +All attributes are read-only. + + cid Card Identifaction Register + csd Card Specific Data Register + scr SD Card Configuration Register (SD only) + date Manufacturing Date (from CID Register) + fwrev Firmware/Product Revision (from CID Register) (SD and MMCv1 only) + hwrev Hardware/Product Revision (from CID Register) (SD and MMCv1 only) + manfid Manufacturer ID (from CID Register) + name Product Name (from CID Register) + oemid OEM/Application ID (from CID Register) + prv Product Revision (from CID Register) (SD and MMCv4 only) + serial Product Serial Number (from CID Register) + erase_size Erase group size + preferred_erase_size Preferred erase size + raw_rpmb_size_mult RPMB partition size + rel_sectors Reliable write sector count + +Note on Erase Size and Preferred Erase Size: + + "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. + +Note on raw_rpmb_size_mult: + "raw_rpmb_size_mult" is a mutliple of 128kB block. + RPMB size in byte is calculated by using the following equation: + RPMB partition size = 128kB x raw_rpmb_size_mult + +SD/MMC/SDIO Clock Gating Attribute +================================== + +Read and write access is provided to following attribute. +This attribute appears only if CONFIG_MMC_CLKGATE is enabled. + + clkgate_delay Tune the clock gating delay with desired value in milliseconds. + +echo <desired delay> > /sys/class/mmc_host/mmcX/clkgate_delay |