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2011-01-04ARM: PL08x: don't manipulate txd->srcbus or txd->dstbus during LLI fillRussell King - ARM Linux
Don't alter any txd->srcbus or txd->dstbus values while building the LLI list. This allows us to see the original dma_addr_t values passed in via the prep_memcpy() method. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: fix fill_bytes calculationRussell King - ARM Linux
The number of bytes we want to fill into any LLI is the minimum of: - number of bytes remaining in the transfer - number of bytes we can transfer in a single LLI - number of bytes we can transfer without overflowing the source boundary - number of bytes we can transfer without overflowing the destination boundary The minimum of the first two is already calculated (target_len). We limit the boundary calculations to this number of bytes, which will then give us the number of bytes we can place into this LLI. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: use min() to calculate target_lenRussell King - ARM Linux
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: ensure pl08x_pre_boundary() works for any value of addrRussell King - ARM Linux
pl08x_pre_boundary() was unsafe with addresses towards the top of memory space: boundary = ((addr >> PL08X_BOUNDARY_SHIFT) + 1) << PL08X_BOUNDARY_SHIFT; This can overflow a 32-bit number, producing zero. When it does: if (boundary < addr + len) return boundary - addr; else return len; results in (boundary - addr) returning either a large positive value. Also if addr + len overflows, this calculation also fails. We can fix this trivially as the only thing we're actually interested in is the value of the least significant PL08X_BOUNDARY_SHIFT bits: boundary_len = PL08X_BOUNDARY_SIZE - (addr & (PL08X_BOUNDARY_SIZE - 1)); gives us the number of bytes before 'addr' becomes a multiple of PL08X_BOUNDARY_SIZE. We can then just take the min() of the two calculated lengths. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: make pl08x_fill_lli_for_desc() return voidRussell King - ARM Linux
We don't need pl08x_fill_lli_for_desc() to return num_llis + 1 as we know that's what it always does. We can just pass in num_llis and use post-increment in the caller. This makes the code slightly easier to read. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: move callback outside spinlock'd regionRussell King - ARM Linux
Calling the callback handler with spinlocks in the tasklet held leads to deadlock when dmaengine functions are called: BUG: spinlock lockup on CPU#0, sh/417, c1870a08 Backtrace: ... [<c017b408>] (do_raw_spin_lock+0x0/0x154) from [<c02c4b98>] (_raw_spin_lock_irqsave+0x54/0x60) [<c02c4b44>] (_raw_spin_lock_irqsave+0x0/0x60) from [<c01f5828>] (pl08x_prep_channel_resources+0x718/0x8b4) [<c01f5110>] (pl08x_prep_channel_resources+0x0/0x8b4) from [<c01f5bb4>] (pl08x_prep_slave_sg+0x120/0x19c) [<c01f5a94>] (pl08x_prep_slave_sg+0x0/0x19c) from [<c01be7a0>] (pl011_dma_tx_refill+0x164/0x224) [<c01be63c>] (pl011_dma_tx_refill+0x0/0x224) from [<c01bf1c8>] (pl011_dma_tx_callback+0x7c/0xc4) [<c01bf14c>] (pl011_dma_tx_callback+0x0/0xc4) from [<c01f4d34>] (pl08x_tasklet+0x60/0x368) [<c01f4cd4>] (pl08x_tasklet+0x0/0x368) from [<c004d978>] (tasklet_action+0xa0/0x100) Dan quoted the documentation: > 2/ Completion callback routines cannot submit new operations.  This >    results in recursion in the synchronous case and spin_locks being >    acquired twice in the asynchronous case. but then followed up to say: > I should clarify, this is the async_memcpy() api requirement which is > not used outside of md/raid5. DMA drivers can and do allow new > submissions from callbacks, and the ones that do so properly move the > callback outside of the driver lock. So let's fix it by moving the callback out of the spinlocked region. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: allow AHB master port selection to be configuredRussell King - ARM Linux
Platforms need to be able to control which AHB master interface is used, as each AHB master interface may be asymetric. Allow the interfaces used for fetching LLIs, memory, and each peripheral to be configured individually. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: move AHB master port selection into prep_* functionsRussell King - ARM Linux
As we initialize the default cctl value in the prep_* functions along with the increment settings, we don't need to repeat the selection of the AHB ports each time we create a LLI entry. Do this in the prep_* functions once per transfer. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: move cctl increment and protection setup to prep_slave_sgRussell King - ARM Linux
We don't need to initialize the cctl increment and protection values in the runtime_config method - we have all the inforamtion to setup these values in prep_slave_sg(). Move their initialization there. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: move default cctl into txd structureRussell King - ARM Linux
Rather than modifying platform data while preparing a transfer, copy the cctl value into the txd structure and modify the value there. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: assign ccfg DMA request signal in prep_phy_channel()Russell King - ARM Linux
There is no need to wait until we start processing a tx descriptor before setting up the DMA request selection in the ccfg register. We know which channel and request will be used in prep_phy_channel(), so setup the ccfg request selection at txd creation time in prep_phy_channel(). Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: move ccfg into txd structureRussell King - ARM Linux
The ccfg register is used to configure the channel parameters - the type and direction of transfer, the flow control signal and IRQ mask enables. The type and direction of transfer is known in the relevent prep_* function where a txd is created. The IRQ mask enables are always set, and the flow control signals are always set when we start processing a txd according to phychan->signal. If we store the ccfg value in the txd structure, we can avoid modifying platform data - and even having it in platform data at all. So, remove it from platform data too. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: avoid duplicating registers in txd and phychan structuresRussell King - ARM Linux
As we now have all the code accessing the phychan {csrc,cdst,clli,cctl, ccfg} members in one function, there's no point storing the data into the struct. Get rid of the struct members. Re-order the register dump in the dev_dbg() to reflect the order we write the registers to the DMA device. The txd {csrc,cdst,clli,cctl} values are duplicates of the lli[0] values, so there's no point duplicating these either. Program the DMAC registers directly from the lli[0] values. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: combine functions to start DMA into one functionRussell King - ARM Linux
There is no need for pl08x_config_phychan_for_txd(), pl08x_set_cregs() and pl08x_enable_phy_chan() to be separate - they are always called in sequence. Combine them into one function. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: clean up LLI lookupRussell King - ARM Linux
As the LLI list is an array, we can use maths to locate which LLI index we're currently at, and then sum up the remaining LLI entries until we reach the end of the list. This makes the code much easier to read, and much less susceptible to falling off the end of the array. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: rename lli.next to lli.lliRussell King - ARM Linux
The LLI pointer in the documentation is placed into the LLI register, so name it LLI rather than 'next'. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: use 'u32' for LLI structure members, not dma_addr_tRussell King - ARM Linux
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: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: use 'size_t' for lengthsRussell King - ARM Linux
Use size_t for variables denoting lengths throughout, and use the 'z' qualifier for printing the value. For safety, add a BUG_ON() in pl08x_fill_lli_for_desc() to catch the remainder potentially becoming negative. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: don't try to use llis_bus as a pointerRussell King - ARM Linux
llis_bus is the DMA address of the LLI array. Casting it to be a pointer just to be able to use pointer arithmetic on it is not nice. We can trivially deal with the places where we do arithmetic on it, and it's actually cleaner this way. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: don't assume that the LLI pointer has the bus bit clearRussell King - ARM Linux
We only want use the address of the LLI pointer when locating the corresponding structure in memory, so clear the master bus selection bit. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: ensure loops use cpu_relax()Russell King - ARM Linux
Tight loops should use cpu_relax() to allow CPUs to reduce power consumption while waiting for events. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: consolidate physical channel release codeRussell King - ARM Linux
Consolidate duplicated channel release code into release_phy_channel() Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: consolidate common txd initializationRussell King - ARM Linux
Consolidate code which allocates and initializes txds. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: avoid 'void *' struct fields when we can type them properlyRussell King - ARM Linux
Avoid using 'void *' struct fields when the structs are not defined in linux/amba/pl08x.h - instead, forward declare the struct names, and use these instead. This ensures we have proper typechecking. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: constify vendor data pointersRussell King - ARM Linux
We should never modify the vendor data structure so make it const. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: remove circular buffer supportRussell King - ARM Linux
The driver already won't initialize a channel with a circular buffer; the check in pl08x_prep_channel_resources() sees to that. Remove circular buffer support for the time being. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: remove unnecessary NULL and BUG checksRussell King - ARM Linux
The tasklet always is initialized with a non-NULL data argument. It is not possible for it to be called with a NULL data argument (unless something is very wrong in the tasklet code - in which case lots of stuff will break). Therefore, as plchan can never be NULL, remove this unnecessary BUG check. In pl08x_tasklet(), we've already dereferenced plchan->at, so it can't be NULL here. Remove this unnecessary BUG check. pl08x_fill_llis_for_desc() and pl08x_free_txd() are always called with a non-NULL txd argument - either as a consequence of the code paths or as a result of other checks already in place. We don't need to repeat the non-NULL check in these functions. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: remove unnecessary includesRussell King - ARM Linux
We don't need to include linux/pci.h as we aren't a PCI driver. We aren't doing any processor specific functions, so asm/processor.h is not required. asm/cacheflush.h shouldn't be used, we have the DMA API for this. DMA interfaces aren't required as we're only implementing the dmaengine API and not a platform-private DMA API. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: prefix hex numbers with 0xRussell King - ARM Linux
A driver which emits both decimal and hex numbers in its printk creates confusion as to what is what. Prefix hex numbers with 0x. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: improve the announcement printkRussell King - ARM Linux
Include the revision number of the PL08x primecell in the boot-time printk to allow proper identification of the peripheral. Reformat the announcement printk format reflect what we do for other primecell drivers - generally "PLXXX revX at 0xNNNNNNNN irq X". Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: add comment explaining the flow control methodsRussell King - ARM Linux
Explain the two flow control methods which the PL08x implements, along with the problem which peripheral flow control presents. This helps people understand why we are unable to use these DMA controllers with (eg) the MMCI. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: fix sparse warningsRussell King - ARM Linux
drivers/dma/amba-pl08x.c:1895:40: warning: Unknown escape '%' drivers/dma/amba-pl08x.c:1903:40: warning: Unknown escape '%' drivers/dma/amba-pl08x.c:513:6: warning: symbol 'pl08x_choose_master_bus' was not declared. Should it be static? drivers/dma/amba-pl08x.c:604:5: warning: symbol 'pl08x_fill_llis_for_desc' was not declared. Should it be static? drivers/dma/amba-pl08x.c:1442:32: warning: symbol 'pl08x_prep_slave_sg' was not declared. Should it be static? Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: fix deadlock in terminate_allRussell King - ARM Linux
Trying to disable a tasklet while holding a spinlock which the tasklet will take is a recipe for deadlock - tasklet_disable() will wait for the tasklet to finish running, which it will never do. In any case, there is not a corresponding tasklet_enable(), so once the tasklet is disabled, it will never run again until reboot. It's safe to just remove the tasklet_disable() as we remove all current and pending descriptors before releasing this spinlock. This means that the tasklet will find no remaining work if it subsequently runs. The only remaining issue is that the callback for an already submitted txd may be in progress, or even called after terminate_all() returns. There's not much that can be done about that as waiting for the callback to complete before returning will also lead to deadlocks. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: fix missed spin-unlock in pl08x_issue_pending()Russell King - ARM Linux
pl08x_issue_pending() returns with the spinlock locked and interrupts disabled if the channel is waiting for a physical DMA to become free. This is wrong - especially as pl08x_issue_pending() is an API function as it leads to deadlocks. Fix it to always return with the spinlock unlocked. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: fix a leak when preparing TXDsRussell King - ARM Linux
If we fail to allocate the LLI, the prep_* function will return NULL. However, the TXD we allocated will not be placed on any list, nor will it be freed - we'll just drop all references to it. Make sure we free it rather than leaking TXDs. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: fix locking in taskletRussell King - ARM Linux
Tasklets are run from an interruptible context. The slave DMA functions can be called from within IRQ handlers. Taking the spinlock without disabling interrupts allows an interrupt handler to run, which may try to take the spinlock again, resulting in deadlock. Fix this by using the irqsave spinlocks. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: fix atomic_t usage and tx_submit() return value rangeRussell King - ARM Linux
The last_issued variable uses an atomic type, which is only incremented inside a protected region, and then read. Everywhere else only reads the value, so it isn't using atomic_t correctly, and it doesn't even need to. Moreover, the DMA engine code provides us with a variable for this already - chan.cookie. Use chan.cookie instead. Also, avoid negative dma_cookie_t values - negative returns from tx_submit() mean failure, yet in reality we always succeed. Restart from cookie 1, just like other DMA engine drivers do. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: fix array overflow in dma_set_runtime_config()Russell King - ARM Linux
If maxburst was passed in as zero, we would overflow the burst_sizes[] array. Fix this by checking for this condition, and defaulting to single transfer 'bursts'. Improve the readability of the loop using a for() loop rather than a while() loop with the iterator initialized far from the loop. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04ARM: PL08x: fix spelling errorsRussell King - ARM Linux
Correct mis-spellings in comments and printk strings. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-04dmaengine: dma40: Add support to split up large elementsPer Forlin
The maximum transfer size of the stedma40 is (64k-1) x data-width. If the transfer size of one element exceeds this limit the job is split up and sent as linked transfer. Signed-off-by: Per Forlin <per.forlin@linaro.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-03Merge branch 'fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx: dmaengine: provide dummy functions for DMA_ENGINE=n mv_xor: fix race in tasklet function
2011-01-03mv_xor: fix race in tasklet functionSaeed Bishara
use mv_xor_slot_cleanup() instead of __mv_xor_slot_cleanup() as the former function aquires the spin lock that needed to protect the drivers data. Cc: <stable@kernel.org> Signed-off-by: Saeed Bishara <saeed@marvell.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2011-01-03Merge branch 'sgu/mxs-core-v8' of git://git.pengutronix.de/git/ukl/linux-2.6 ↵Sascha Hauer
into imx-for-2.6.38-new
2010-12-29powerpc/512x: try to free dma descriptors in case of allocation failureIlya Yanok
Currently completed descriptors are processed in the tasklet. This can lead to dead lock in case of CONFIG_NET_DMA enabled (new requests are submitted from softirq context and dma_memcpy_to_iovec() busy loops until the requests is submitted). To prevent this we should process completed descriptors from the allocation failure path in prepare_memcpy too. Signed-off-by: Ilya Yanok <yanok@emcraft.com> Cc: Piotr Ziecik <kosmo@semihalf.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-29powerpc/512x: add MPC8308 dma supportIlya Yanok
MPC8308 has pretty much the same DMA controller as MPC5121 and this patch adds support for MPC8308 to the mpc512x_dma driver. Signed-off-by: Ilya Yanok <yanok@emcraft.com> Acked-by: Wolfgang Denk <wd@denx.de> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-29powerpc/512x: fix the hanged dma transfer issueIlya Yanok
Current code clears interrupt active status _after_ submitting new transfers. This leaves a possibility of clearing the interrupt for this new transfer (if it is triggered fast enough) and thus lose this interrupt. We want to clear interrupt active status _before_ new transfers is submitted and for current channel only. Signed-off-by: Ilya Yanok <yanok@emcraft.com> Acked-by: Wolfgang Denk <wd@denx.de> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-29powerpc/512x: scatter/gather dma fixIlya Yanok
While testing mpc512x-dma driver with dmatest module I've found that I can hang the mpc512x-dma issuing request from multiple threads to the single channel. insmod dmatest.ko max_channels=1 threads_per_chan=16 After investigating this case I've managed to find that this happens if and only if we have more than one queued requests. In this case the driver tries to make use of hardware scatter/gather functionality. I've found two problems with scatter/gather: 1. When TCD is copied form RAM to the TCD register space with memcpy_io() e_sg bit eventually gets cleared. This results in only first TCD being executed. I've added setting of e_sg bit explicitly in the TCD registers. BTW, what is the correct way to do this? (How can I use setbits with bitfield structure?) After that hardware loads consecutive TCDs and we hit the second issue. 2. Existing code clears int_maj bit in the last TCD so we never get an interrupt on transfer completion. With these fixes my tests with many threads of single channel succeed but tests that use many channels simultaneously still don't work reliable. Signed-off-by: Ilya Yanok <yanok@emcraft.com> Acked-by: Wolfgang Denk <wd@denx.de> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2010-12-22Merge branch 'master' into for-nextJiri Kosina
Conflicts: MAINTAINERS arch/arm/mach-omap2/pm24xx.c drivers/scsi/bfa/bfa_fcpim.c Needed to update to apply fixes for which the old branch was too outdated.
2010-12-17dma: shdma: NMI support.Paul Mundt
Presently DMA transfers are interrupted and aborted by the NMI. This implements some basic logic for more gracefully handling and clearing each controller's NMIF flag via the NMI die chain, needed to resume transfers post-NMI. Reported-by: Michael Szafranek <Michael.Szafranek@emtrion.de> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2010-12-14Merge branch 'fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/async_tx: dmaengine: at_hdmac: fix buffer transfer size specification fsldma: fix issue of slow dma dmaengine i.MX SDMA: initialize on module_init dma : EG20T PCH: Fix miss-setting DMA descriptor intel_mid_dma: fix section mismatch warnings dmaengine: imx-sdma: fix bug in buffer descriptor initialization drivers/dma/ppc4xx: Use printf extension %pR for struct resource drivers/dma/ioat: Use the ccflag-y instead of EXTRA_CFLAGS drivers/dma/: Use the ccflag-y instead of EXTRA_CFLAGS dma: intel_mid_dma: fix double free on mid_setup_dma error path dma: imx-dma: fix imxdma_probe error path