mmc: block: flush request requeue after timeout.

On some eMMC cards cache flush is taking longer than 30 sec timeout
after HPI issued and -EIO reported to the upper layers. This may result
into journaling issues as flush calls are issued by the file system
joulrnaling code.

This change increases flash cache timeout to 90 sec, in case of timeout
occurs, after HPI issued, flash request re-queued to the block layer queue
to execute it later and keep journaling logic valid.

Conflicts:
	drivers/mmc/card/block.c

Change-Id: I1e968c07056062fd9c8e14e5bc3e62b3b4b99c64
Signed-off-by: Panwar Vivek <vpanwa@codeaurora.org>

Conflicts:

	drivers/mmc/card/block.c

Signed-off-by: Maya Erez <merez@codeaurora.org>

Conflicts:

	drivers/mmc/card/block.c
mmc: core: increase timeout for disable cache operation

According to eMMC specification, there is no upper bound defined on
a flush request and the duration of flush operation is left to card
vendor's implementation. This means that it may take a very long
time to complete.

When eMMC cache is disabled, the card has to flush all the data in its
cache. So this means that for certain cards, the driver is not waiting
long enough for the flush to complete during cache disable operation,
leading to data on the card being corrupted.

This change increases the timeout for cache disable operation, thus
preventing data corruption.

CRs-Fixed: 562350
Change-Id: If68328ab56b50c7596800f07ef92c0ab16a55ec0
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: David Ng <dave@codeaurora.org>
Signed-off-by: Krishna Konda <kkonda@codeaurora.org>
workqueue: Added null check and warning

If work item is already in queue get_work_cwq() will return null.
so null check is added to avoid crash in delayed_work_timer_on()

CRs-Fixed: 586162

Change-Id: I5c885142fd72781cea90d6c9b3456ecc7f0778b6
Signed-off-by: Srinivasarao P <spathi@codeaurora.org>