Commit graph

310471 commits

Author SHA1 Message Date
Uwe Kleine-König 7fd63ccdad dmaengine: at_hdmac: add a few const qualifiers
This prepares of_device_id.data becoming const. Without this change
the following warning would occur:

	drivers/dma/at_hdmac.c: In function 'at_dma_get_driver_data':
	drivers/dma/at_hdmac.c:1228: warning: return discards qualifiers from pointer target type

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Vinod Koul <vinod.koul@intel.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-07-16 12:05:45 +05:30
Andy Shevchenko f8609c2b52 dw_dmac: use 'u32' for LLI structure members, not dma_addr_t
Use 'u32' for the LLI structure members, which are defined by hardware to be
32-bit. dma_addr_t is much more vague about its actual size.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-07-16 12:03:07 +05:30
Andy Shevchenko 93aad1bcc5 dw_dmac: mark dwc_dump_lli inline
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-07-16 12:03:07 +05:30
Attila Kinali 41c556a8cb dma: mxs-dma: Export missing symbols from mxs-dma.c
mxs-dma.c provides two functions mxs_dma_is_apbh and mxs_dma_is_apbx
which are used at least in mxs-mmc.c. Building mxs-mmc as module
fails due to those two symbols not being exported.

Signed-off-by: Attila Kinali <attila@kinali.ch>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-07-16 11:59:22 +05:30
Guennadi Liakhovetski ce3a1ab742 dma: shdma: convert to the shdma base library
The shdma base library has originally been extracted from the shdma driver,
which now can be converted to actually use it.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-07-13 09:13:08 +05:30
Guennadi Liakhovetski b8373147ed ASoC: fsi: prepare for conversion to the shdma base library
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Liam Girdwood <lrg@ti.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-07-13 09:13:08 +05:30
Guennadi Liakhovetski f19b7e0db7 usb: renesas_usbhs: prepare for conversion to the shdma base library
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-07-13 09:13:08 +05:30
Guennadi Liakhovetski 6f3de8bf33 ASoC: siu: prepare for conversion to the shdma base library
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Liam Girdwood <lrg@ti.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-07-13 09:13:08 +05:30
Guennadi Liakhovetski d6fa5a4e7a serial: sh-sci: prepare for conversion to the shdma base library
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Alan Cox <alan@linux.intel.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-07-13 09:13:08 +05:30
Guennadi Liakhovetski c471270d7a mmc: sh_mobile_sdhi: prepare for conversion to the shdma base library
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Chris Ball <cjb@laptop.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-07-13 09:13:07 +05:30
Guennadi Liakhovetski 916001fe33 mmc: sh_mmcif: remove unneeded struct sh_mmcif_dma, prepare to shdma conversion
Now that all users have been updated to use the embedded in struct
sh_mmcif_plat_data DMA slave IDs, struct sh_mmcif_dma is no longer needed
and can be removed. This also makes preparation to the shdma base library
conversion easier.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Chris Ball <cjb@laptop.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-07-13 09:13:07 +05:30
Guennadi Liakhovetski 5902c9a7a2 dma: shdma: prepare for conversion to the shdma base library
By placing an anonymous union at the top of struct sh_dmae_slave we can
transparently prepare all device and client drivers for the upcoming
shdma-base conversion.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-07-13 09:13:07 +05:30
Guennadi Liakhovetski 9a7b8e002e dmaengine: add an shdma-base library
This patch extracts code from shdma.c, that does not directly deal with
hardware implementation details and can be re-used with diverse DMA
controller variants, found on SH-based SoCs.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-07-13 09:13:07 +05:30
Guennadi Liakhovetski e95be94b8c dma: move shdma driver to an own directory
The shdma driver is going to be split into multiple files. To make this more
convenient move it to an own directory.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-07-13 09:12:59 +05:30
Laxman Dewangan cd9092c6ea dma: tegra: rename driver and compatible to match with dts
Rename the compatible name and driver name to match with
tegra dts file and as per clock driver.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-07-13 08:49:54 +05:30
Laxman Dewangan 4a46ba36e2 dma: tegra: fix residual calculation for cyclic case
In cyclic mode of DMA, the byte transferred can be more
than the requested size and in this case, calculating
residuals based on the current position of DMA transfer to
bytes requested i.e. bytes required to transfer to reach
bytes requested from current DMA position.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-07-13 08:49:54 +05:30
Laxman Dewangan 46fb3f8ef5 dma: tegra: set DMA_CYCLIC capability
Tegra's APB DMA driver support the cyclic mode of data
transfer and hence setting the DMA_CYCLIC caps for dma
channels.

This is require when generic sound dmaengine pcm driver
request for dma channel with CYCLIC capability.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-27 19:18:55 +05:30
Laxman Dewangan 6660f7af52 dma: tegra: do not set transfer desc flag to DMA_CTRL_ACK in cyclic mode
The sound dmaengine pcm driver uses the dma in cyclic mode and
it does not ack the transfer descriptor  after transfer stops.
This may lead to hold that desc in chip's dma driver and does
not allow to reuse/free that descriptors. Hence not enabling
flag DMA_CTRL_ACK when dma runs in cyclic mode.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-27 19:18:55 +05:30
Prashant Gaikwad 56482ec0b1 dma: tegra: add clk_prepare/clk_unprepare
Use clk_prepare/clk_unprepare as required by the generic clk framework.

Signed-off-by: Prashant Gaikwad <pgaikwad@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-27 19:03:25 +05:30
Laxman Dewangan 597c854974 dma: tegra: use sg_dma_address() for getting dma buffer address
Use the sg_dma_address() to get the segment buffer address for
DMA transfer in place of sg_phys() which returns the physical
address of an sg entry.
The sg_dma_address() returns the correct buffer memory address
for DMA transfer.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-27 19:01:52 +05:30
Vinod Koul 49d57b5e58 dmaengine: mmp_tdma: fix the arch dependency
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-23 13:14:17 +05:30
Andy Shevchenko 3f9362078b dw_dmac: introduce dwc_chan_disable
This piece of code is used often. Make it as a separate function.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.linux@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-21 08:05:39 +05:30
Andy Shevchenko 0272e93f36 dw_dmac: move from __init to __devinit
We usually have more than one DMA device. Thus, the probe function should serve
for all of them in case when the driver is built as a module.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.linux@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-21 08:05:38 +05:30
Andy Shevchenko 4c2d56c574 dw_dmac: introduce dwc_fast_fls()
There were three places where such function is used. We still avoid to use
native fls() because in one case it requires to use 64bit version which is
suboptimal in our case.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.linux@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-21 08:05:38 +05:30
Andy Shevchenko 236b106f1a dw_dmac: disable BLOCK interrupts
Just to be sure we are in known state we disable the BLOCK interupts.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.linux@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-21 08:05:37 +05:30
Andy Shevchenko 11f932ec22 dw_dmac: disable dma in optimal way in probe
The dw_dma_off call needs to have the all_chan_mask calculated. So, done this
calculations before the call. Moreover, remove duplicate code that masks the
DMA interrupts.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.linux@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-21 08:05:36 +05:30
Andy Shevchenko 2e4c364e15 dw_dmac: use __func__ constant in the debug prints
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.linux@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-21 08:05:35 +05:30
Andy Shevchenko 2ab3727634 dw_dmac: print correct number of scanned descriptors
In case the first descriptor we found is available, the counter still remains 0
value which is wrong. This patch fixes the counter behaviour.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.linux@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-21 08:05:34 +05:30
Andy Shevchenko 1d45543765 dw_dmac: introduce dwc_dump_chan_regs to dump registers
There is three places where values of the most significant registers were
printed. Make such piece of code as separate function.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.linux@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-21 08:05:34 +05:30
Andy Shevchenko 2f45d613ff dw_dmac: use proper casting to print dma_addr_t values
dma_addr_t is sometimes 32 bit and sometimes 64. We normally cast them to
unsigned long long for printk().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.linux@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-21 08:05:33 +05:30
Andy Shevchenko 745664ebe0 dw_dmac: fix constant in the comment
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Viresh Kumar <viresh.linux@gmail.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-21 08:05:32 +05:30
Zhangfei Gao c6da0ba8df dmaengine: mmp_tdma: add mmp tdma support
Add support for two-channel dma under dmaengine
support: mmp-adma and pxa910-squ

Signed-off-by: Zhangfei Gao <zhangfei.gao@marvell.com>
Signed-off-by: Leo Yan <leoy@marvell.com>
Signed-off-by: Qiao Zhou <zhouqiao@marvell.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-20 16:28:41 +05:30
Lars-Peter Clausen 3052cc2c92 dmaengine: Add wrapper for device_tx_status callback
This patch adds a small inline wrapper for the devivce_tx_status callback of a
dma device. This makes the source code of users of this function a bit more
compact and a bit more legible.

E.g.:
-status = chan->device->device_tx_status(chan, cookie, &state)
+status = dmaengine_tx_status(chan, cookie, &state)

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-20 16:23:16 +05:30
Vinod Koul 0a0760358c Merge branch 'fixes' into next 2012-06-14 11:20:31 +05:30
Linus Walleij f7ceb362c4 dma: coh901318: use devm allocation
Allocate memory, region, remap and irq for device state using
devm_* helpers to simplify memory accounting.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-14 08:42:26 +05:30
Javi Merino fdec53d520 DMA: PL330: Fix racy mutex unlock
pl330_update() stores a pointer to the thrd->req that finished, which
contains a pointer to the corresponding pl330_req.  This is done with
the pl330_lock held.  Then, it iterates through the req_done list,
calling the callback for each of the requests that are done.  The
problem is that the driver releases the lock before calling the
callback for each of the callbacks.  pl330_submit_req() running in
another processor can then acquire the lock and insert another request
in one of the thrd->req that hasn't been processed yet, replacing the
pointer to pl330_req there.  When the callback returns in
pl330_update() and the next rqdone is popped from the list, it
dereferences the pl330_req pointer to the just scheduled pl330_req,
instead of the one that has finished, calling pl330 with the wrong r.

This patch fixes this by storing the pointer to pl330_req directly in
the list.

Signed-off-by: Javi Merino <javi.merino@arm.com>
Cc: Jassi Brar <jaswinder.singh@linaro.org>
Acked-by: Jassi Brar <jaswinder.singh@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-14 08:39:52 +05:30
Nicolas Ferre 9102d8715e dmaengine: at_hdmac: trivial: fix comment in header
Not all Atmel SoCs were pointed out in header comment which was bringing
confusion. Remove the truncated list of supported devices, replace by the
only one that is not supported.

Reported-by: Elen Song <elen.song@atmel.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-12 14:43:54 +05:30
Laxman Dewangan ec8a158678 dma: tegra: add dmaengine based dma driver
Add dmaengine based NVIDIA's Tegra APB DMA driver.
This driver support the slave mode of data transfer from
peripheral to memory and vice versa.
The driver supports for the cyclic and non-cyclic mode
of data transfer.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-08 10:53:05 +05:30
Laxman Dewangan 4fd1e324b7 dma: dmaengine: add slave req id in slave_config
The DMA controller like Nvidia's Tegra Dma controller
supports the different slave requestor id from different slave.
This need to be configure in dma controller to handle the request
properly.

Adding the slave-id in the slave configuration so that information
can be passed from client when configuring for slave.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-08 10:53:05 +05:30
Huang Shijie f5c55847f7 dma: enable mxs-dma for imx6q
enable the mxs-dma for imx6q.
Also remove the unused header file.

Signed-off-by: Huang Shijie <shijie8@gmail.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-07 14:55:37 +05:30
Sachin Kamat 5a67ac572e DMA: PL330: Add missing static storage class specifier
Fixes the following sparse warning:
drivers/dma/pl330.c:2542:5: warning: symbol 'add_desc' was not declared. Should it be static?

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-07 13:53:25 +05:30
Richard Zhao 8e2e27c744 dma: imx-sdma: buf_tail should be initialize in prepare function
This fix audio underrun issue. When SNDRV_PCM_TRIGGER_STOP
and SNDRV_PCM_TRIGGER_START, it calls prepare again. buf_tail
should be reset to zero.
So move buf_tail initialization into prepare function.

Signed-off-by: Richard Zhao <richard.zhao@freescale.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
2012-06-07 13:48:42 +05:30
Tushar Behera 30c1dc0ff3 dmaengine: pl330: dont complete descriptor for cyclic dma
Commit eab2158558 ("dmaengine: pl330: dont complete descriptor for
cyclic dma") wrongly completes descriptor for cyclic dma, hence following
BUG_ON is still hit with cyclic DMA operations.

kernel BUG at drivers/dma/dmaengine.h:53!

Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Acked-by: Jassi Brar <jaswinder.singh@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
2012-06-07 13:42:58 +05:30
Linus Torvalds f8f5701bda Linux 3.5-rc1 2012-06-02 18:29:26 -07:00
Linus Torvalds 912afc3616 Improve multipath's retrying mechanism in some defined circumstances
and provide a simple reserve/release mechanism for userspace tools to
 access thin provisioning metadata while the pool is in use.
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Merge tag 'dm-3.5-changes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm

Pull device-mapper updates from Alasdair G Kergon:
 "Improve multipath's retrying mechanism in some defined circumstances
  and provide a simple reserve/release mechanism for userspace tools to
  access thin provisioning metadata while the pool is in use."

* tag 'dm-3.5-changes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-dm:
  dm thin: provide userspace access to pool metadata
  dm thin: use slab mempools
  dm mpath: allow ioctls to trigger pg init
  dm mpath: delay retry of bypassed pg
  dm mpath: reduce size of struct multipath
2012-06-02 17:39:40 -07:00
Joe Thornber cc8394d86f dm thin: provide userspace access to pool metadata
This patch implements two new messages that can be sent to the thin
pool target allowing it to take a snapshot of the _metadata_.  This,
read-only snapshot can be accessed by userland, concurrently with the
live target.

Only one metadata snapshot can be held at a time.  The pool's status
line will give the block location for the current msnap.

Since version 0.1.5 of the userland thin provisioning tools, the
thin_dump program displays the msnap as follows:

    thin_dump -m <msnap root> <metadata dev>

Available here: https://github.com/jthornber/thin-provisioning-tools

Now that userland can access the metadata we can do various things
that have traditionally been kernel side tasks:

     i) Incremental backups.

     By using metadata snapshots we can work out what blocks have
     changed over time.  Combined with data snapshots we can ensure
     the data doesn't change while we back it up.

     A short proof of concept script can be found here:

     https://github.com/jthornber/thinp-test-suite/blob/master/incremental_backup_example.rb

     ii) Migration of thin devices from one pool to another.

     iii) Merging snapshots back into an external origin.

     iv) Asyncronous replication.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-06-03 00:30:01 +01:00
Mike Snitzer a24c25696b dm thin: use slab mempools
Use dedicated caches prefixed with a "dm_" name rather than relying on
kmalloc mempools backed by generic slab caches so the memory usage of
thin provisioning (and any leaks) can be accounted for independently.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-06-03 00:30:00 +01:00
Mikulas Patocka 35991652ba dm mpath: allow ioctls to trigger pg init
After the failure of a group of paths, any alternative paths that
need initialising do not become available until further I/O is sent to
the device.  Until this has happened, ioctls return -EAGAIN.

With this patch, new paths are made available in response to an ioctl
too.  The processing of the ioctl gets delayed until this has happened.

Instead of returning an error, we submit a work item to kmultipathd
(that will potentially activate the new path) and retry in ten
milliseconds.

Note that the patch doesn't retry an ioctl if the ioctl itself fails due
to a path failure.  Such retries should be handled intelligently by the
code that generated the ioctl in the first place, noting that some SCSI
commands should not be retried because they are not idempotent (XOR write
commands).  For commands that could be retried, there is a danger that
if the device rejected the SCSI command, the path could be errorneously
marked as failed, and the request would be retried on another path which
might fail too.  It can be determined if the failure happens on the
device or on the SCSI controller, but there is no guarantee that all
SCSI drivers set these flags correctly.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-06-03 00:29:58 +01:00
Mike Christie f220fd4efb dm mpath: delay retry of bypassed pg
If I/O needs retrying and only bypassed priority groups are available,
set the pg_init_delay_retry flag to wait before retrying.

If, for example, the reason for the bypass is that the controller is
getting reset or there is a firmware upgrade happening, retrying right
away would cause a flood of log messages and retries for what could be a
few seconds or even several minutes.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-06-03 00:29:45 +01:00
Mike Snitzer 1fbdd2b3a3 dm mpath: reduce size of struct multipath
Move multipath structure's 'lock' and 'queue_size' members to eliminate
two 4-byte holes.  Also use a bit within a single unsigned int for each
existing flag (saves 8-bytes).  This allows future flags to be added
without each consuming an unsigned int.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2012-06-03 00:29:43 +01:00