linux/drivers/dma, branch v4.3

Merge tag 'dmaengine-fix-4.3-rc4' of git://git.infradead.org/users/vkoul/slave-dma

2015-10-02T18:46:15Z

Pull dmaengine fixes from Vinod Koul: "This contains fixes spread throughout the drivers, and also fixes one more instance of privatecnt in dmaengine. Driver fixes summary: - bunch of pxa_dma fixes for reuse of descriptor issue, residue and no-requestor - odd fixes in xgene, idma, sun4i and zxdma - at_xdmac fixes for cleaning descriptor and block addr mode" * tag 'dmaengine-fix-4.3-rc4' of git://git.infradead.org/users/vkoul/slave-dma: dmaengine: pxa_dma: fix residue corner case dmaengine: pxa_dma: fix the no-requestor case dmaengine: zxdma: Fix off-by-one for testing valid pchan request dmaengine: at_xdmac: clean used descriptor dmaengine: at_xdmac: change block increment addressing mode dmaengine: dw: properly read DWC_PARAMS register dmaengine: xgene-dma: Fix overwritting DMA tx ring dmaengine: fix balance of privatecnt dmaengine: sun4i: fix unsafe list iteration dmaengine: idma64: improve residue estimation dmaengine: xgene-dma: fix handling xgene_dma_get_ring_size result dmaengine: pxa_dma: fix initial list move

dmaengine: pxa_dma: fix residue corner case

2015-10-01T02:14:31Z

A very tiny temporal window exists in the residue calculation where : - upon entering residue calculation, the transfer is ongoing - when reading the current transfer pointer, it just changed to the "finisher/linker" descriptor In this case, the residue returned is the whole transfer length instead of 0. Fix it. This appears almost in one extreme case, where the driver is used by older clients which inquire for residue in interrupt context, such as the smsc91x ethernet driver, in a tight loop : interrupt_handler() dmaengine_submit() do { dmaengine_tx_status() } while (residue > 0 || status != DMA_ERROR) Signed-off-by: Robert Jarzmik Signed-off-by: Vinod Koul

dmaengine: pxa_dma: fix the no-requestor case

2015-10-01T02:14:25Z

A very small number of devices don't use the flow control offered by requestor lines. In these specific cases, the pxa dma driver should be aware of that and not try to use a requestor line. Signed-off-by: Robert Jarzmik Signed-off-by: Vinod Koul

dmaengine: zxdma: Fix off-by-one for testing valid pchan request

2015-10-01T02:12:27Z

The valid pchan range is 0 ~ d->dma_requests - 1. Signed-off-by: Axel Lin Reviewed-by: Jun Nie Signed-off-by: Vinod Koul

dmaengine: at_xdmac: clean used descriptor

2015-10-01T01:59:49Z

When putting back a descriptor to the free descs list, some fields are not set to 0, it can cause bugs if someone uses it without having this in mind. Descriptor are not put back one by one so it is easier to clean descriptors when we request them. Signed-off-by: Ludovic Desroches Cc: stable@vger.kernel.org #4.2 Signed-off-by: Vinod Koul

dmaengine: at_xdmac: change block increment addressing mode

2015-10-01T01:59:40Z

The addressing mode we were using was not only incrementing the address at each microblock, but also at each data boundary, which was severely slowing the transfer, without any benefit since we were not using the data stride. Switch to the micro block increment only in order to get back to an acceptable performance level. Signed-off-by: Maxime Ripard Signed-off-by: Ludovic Desroches Fixes: 6007ccb57744 ("dmaengine: xdmac: Add interleaved transfer support") Cc: stable@vger.kernel.org #4.2 Signed-off-by: Vinod Koul

dmaengine: dw: properly read DWC_PARAMS register

2015-09-30T08:12:02Z

In case we have less than maximum allowed channels (8) and autoconfiguration is enabled the DWC_PARAMS read is wrong because it uses different arithmetic to what is needed for channel priority setup. Re-do the caclulations properly. This now works on AVR32 board well. Fixes: fed2574b3c9f (dw_dmac: introduce software emulation of LLP transfers) Cc: yitian.bu@tangramtek.com Signed-off-by: Andy Shevchenko Signed-off-by: Vinod Koul

dmaengine: xgene-dma: Fix overwritting DMA tx ring

2015-09-30T08:04:43Z

This patch fixes an over flow issue with the TX ring descriptor. Each descriptor is 32B in size and an operation requires 2 of these descriptors. Signed-off-by: Rameshwar Prasad Sahu Signed-off-by: Vinod Koul

dmaengine: fix balance of privatecnt

2015-09-30T08:00:08Z

dma_release_channel() decrements privatecnt counter and almost all dma_get* function increments it with the exception of dma_get_slave_channel(). In most cases this does not cause issue since normally the channel is not requested and released, but if a driver requests DMA channel via dma_get_slave_channel() and releases the channel the privatecnt will be unbalanced and this will prevent for example getting channel for memcpy. Signed-off-by: Peter Ujfalusi Signed-off-by: Vinod Koul

dmaengine: sun4i: fix unsafe list iteration

2015-09-30T06:47:22Z

Currently, sun4i_dma_free_contract iterates over lists and frees memory as it goes through them, causing reads to recently freed memory to be performed. Fix this by using the safe version of the iterator, so freed memory is not referenced at all. Reported-by: Dan Carpenter Signed-off-by: Emilio López Acked-by: Maxime Ripard Signed-off-by: Vinod Koul