linux.git/drivers/mmc/card/queue.h, branch v3.14

mmc: block: fix the host's claim-release in special request

2013-03-22T17:29:36+00:00

For normal request mmc_blk_issue_rq is called twice with asynchronous
transfer(cur and prev). Host's claim and release can be done in each
mmc_blk_issue_rq. However, Special request is currently excluded in
asynchronous transfer. After special request is finished, if there is
no new request, mmc_release_host won't be called in mmc_blk_issue_rq.
The problem is founded during mmc_suspend.

[] (__schedule+0x0/0x78c) from [] (schedule+0x38/0x78)
[] (schedule+0x0/0x78) from [] (__mmc_claim_host+0xac/0x1b4)
[] (__mmc_claim_host+0x0/0x1b4) from [] (mmc_suspend+0x28/0x9c)
[] (mmc_suspend+0x0/0x9c) from [] (mmc_suspend_host+0xb4/0x194)
...

Reported-by: Johan Rudholm 
Signed-off-by: Seungwon Jeon 
Tested-by: Johan Rudholm 
Signed-off-by: Chris Ball

mmc: support packed write command for eMMC4.5 devices

2013-02-24T19:37:16+00:00

This patch supports packed write command of eMMC4.5 devices.  Several
writes can be grouped in packed command and all data of the individual
commands can be sent in a single transfer on the bus. Large amounts of
data in one transfer rather than several data of small size are
effective for eMMC write internally.  As a result, packed command help
write throughput be improved.  The following tables show the results
of packed write.

Type A:
test     none |  packed
iozone   25.8 |  31
tiotest  27.6 |  31.2
lmdd     31.2 |  35.4

Type B:
test     none |  packed
iozone   44.1 |  51.1
tiotest  47.9 |  52.5
lmdd     51.6 |  59.2

Type C:
test     none |  packed
iozone   19.5 |  32
tiotest  19.9 |  34.5
lmdd     22.8 |  40.7

Signed-off-by: Seungwon Jeon 
Reviewed-by: Maya Erez 
Reviewed-by: Namjae Jeon 
Signed-off-by: Chris Ball

mmc: fix async request mechanism for sequential read scenarios

2013-02-11T18:28:49+00:00

When current request is running on the bus and if next request fetched
by mmcqd is NULL, mmc context (mmcqd thread) gets blocked until the
current request completes. This means that if new request comes in while
the mmcqd thread is blocked, this new request can not be prepared in
parallel to current ongoing request. This may result in delaying the new
request execution and increase it's latency.

This change allows to wake up the MMC thread on new request arrival.
Now once the MMC thread is woken up, a new request can be fetched and
prepared in parallel to the current running request which means this new
request can be started immediately after the current running request
completes.

With this change read throughput is improved by 16%.

Signed-off-by: Konstantin Dorfman 
Reviewed-by: Seungwon Jeon 
Signed-off-by: Chris Ball

mmc: block: add handling for two parallel block requests in issue_rw_rq

2011-07-20T21:21:15+00:00

Change mmc_blk_issue_rw_rq() to become asynchronous.
The execution flow looks like this:

* The mmc-queue calls issue_rw_rq(), which sends the request
  to the host and returns back to the mmc-queue.
* The mmc-queue calls issue_rw_rq() again with a new request.
* This new request is prepared in issue_rw_rq(), then it waits for
  the active request to complete before pushing it to the host.
* When the mmc-queue is empty it will call issue_rw_rq() with a NULL
  req to finish off the active request without starting a new request.

Signed-off-by: Per Forlin 
Acked-by: Kyungmin Park 
Acked-by: Arnd Bergmann 
Reviewed-by: Venkatraman S 
Tested-by: Sourav Poddar 
Tested-by: Linus Walleij 
Signed-off-by: Chris Ball

mmc: queue: add a second mmc queue request member

2011-07-20T21:21:15+00:00

Add an additional mmc queue request instance to make way for two active
block requests. One request may be active while the other request is
being prepared.

Signed-off-by: Per Forlin 
Acked-by: Kyungmin Park 
Acked-by: Arnd Bergmann 
Reviewed-by: Venkatraman S 
Tested-by: Sourav Poddar 
Tested-by: Linus Walleij 
Signed-off-by: Chris Ball

mmc: block: add member in mmc queue struct to hold request data

2011-07-20T21:21:13+00:00

The way the request data is organized in the mmc queue struct, it only
allows processing of one request at a time.  This patch adds a new struct
to hold mmc queue request data such as sg list, request, blk request and
bounce buffers, and updates any functions depending on the mmc queue
struct. This prepares for using multiple active requests in one mmc queue.

Signed-off-by: Per Forlin 
Acked-by: Kyungmin Park 
Acked-by: Arnd Bergmann 
Reviewed-by: Venkatraman S 
Tested-by: Sourav Poddar 
Tested-by: Linus Walleij 
Signed-off-by: Chris Ball

mmc: queue: append partition subname to queue thread name

2011-06-25T22:52:57+00:00

For example, an eMMC with 2 boot partitions will have 3 threads.
The names change from:

   40 ?        00:00:00 mmcqd/0
   41 ?        00:00:00 mmcqd/0
   42 ?        00:00:00 mmcqd/0

to:

   40 ?        00:00:00 mmcqd/0
   41 ?        00:00:00 mmcqd/0boot0
   42 ?        00:00:00 mmcqd/0boot1

Signed-off-by: Adrian Hunter 
Cc: Andrei Warkentin 
Signed-off-by: Chris Ball

mmc: bounce requests for simple hosts

2007-07-09T19:22:53+00:00

Some hosts cannot do scatter/gather in hardware. Since not doing sg
is such a big performance hit, we (optionally) bounce the requests
to a simple linear buffer that we hand over to the driver.

Signed-off-by: Pierre Ossman

mmc: clean up unused parts of block driver

2007-05-24T04:51:02+00:00

Remove dead code and unused structs from the block driver.

Signed-off-by: Pierre Ossman

mmc: Move host and card drivers to subdirs

2007-05-01T11:04:17+00:00

Clean up the drivers/mmc directory by moving card and host drivers
into subdirectories.

Signed-off-by: Pierre Ossman