From 157552575a14a71b923821641551c98df94055f3 Mon Sep 17 00:00:00 2001 From: Vladimir Barinov Date: Sun, 10 Dec 2017 23:51:43 +0300 Subject: DMAC fixes - Backport RCAR DMAC fixes from upstream - Reeneable DMA for SCIF0 on R8A7797 --- ...as-r8a7797-Add-Renesas-R8A7797-SoC-suppor.patch | 4 +- ...car-dmac-ensure-CHCR-DE-bit-is-actually-0.patch | 87 +++++++++++++++++ ...car-dmac-use-TCRB-instead-of-TCR-for-resi.patch | 108 +++++++++++++++++++++ 3 files changed, 197 insertions(+), 2 deletions(-) create mode 100644 meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0080-dmaengine-rcar-dmac-ensure-CHCR-DE-bit-is-actually-0.patch create mode 100644 meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0081-dmaengine-rcar-dmac-use-TCRB-instead-of-TCR-for-resi.patch diff --git a/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0018-arm64-renesas-r8a7797-Add-Renesas-R8A7797-SoC-suppor.patch b/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0018-arm64-renesas-r8a7797-Add-Renesas-R8A7797-SoC-suppor.patch index 68570b3..d6726a3 100644 --- a/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0018-arm64-renesas-r8a7797-Add-Renesas-R8A7797-SoC-suppor.patch +++ b/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0018-arm64-renesas-r8a7797-Add-Renesas-R8A7797-SoC-suppor.patch @@ -696,8 +696,8 @@ index 0000000..6eaa5ba + <&scif_clk>; /* RMSTPCR2/bit7:SCIF0 */ + /*clock-names = "fck", "sck", "brg_int", "scif_clk"; */ + clock-names = "fck"; -+// dmas = <&dmac1 0x51>, <&dmac1 0x50>; -+// dma-names = "tx", "rx"; ++ dmas = <&dmac1 0x51>, <&dmac1 0x50>; ++ dma-names = "tx", "rx"; + power-domains = <&sysc R8A7797_PD_ALWAYS_ON>; + status = "disabled"; + }; diff --git a/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0080-dmaengine-rcar-dmac-ensure-CHCR-DE-bit-is-actually-0.patch b/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0080-dmaengine-rcar-dmac-ensure-CHCR-DE-bit-is-actually-0.patch new file mode 100644 index 0000000..e1597ea --- /dev/null +++ b/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0080-dmaengine-rcar-dmac-ensure-CHCR-DE-bit-is-actually-0.patch @@ -0,0 +1,87 @@ +From a8d46a7f5d17ca9cbe9e9c7d1d23dc6ea437e141 Mon Sep 17 00:00:00 2001 +From: Kuninori Morimoto +Date: Fri, 17 Nov 2017 11:00:28 +0900 +Subject: [PATCH 1/2] dmaengine: rcar-dmac: ensure CHCR DE bit is actually 0 + after clearing + +DMAC reads data from source device, and buffered it until transferable +size for sink device. Because of this behavior, DMAC is including +buffered data . + +Now, CHCR DE bit is controlling DMA transfer enable/disable. + +If DE bit was cleared during data transferring, or during buffering, +it will flush buffered data if source device was peripheral device +(The buffered data will be removed if source device was memory). +Because of this behavior, driver should ensure that DE bit is actually +0 after clearing. + +This patch adds new rcar_dmac_chcr_de_barrier() and call it after CHCR +register access. + +Signed-off-by: Kuninori Morimoto +Tested-by: Hiroyuki Yokoyama +Tested-by: Ryo Kodama +Tested-by: Geert Uytterhoeven +Signed-off-by: Vinod Koul +--- + drivers/dma/sh/rcar-dmac.c | 22 ++++++++++++++++++++++ + 1 file changed, 22 insertions(+) + +diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c +index 2b2c7db..c99fd0f 100644 +--- a/drivers/dma/sh/rcar-dmac.c ++++ b/drivers/dma/sh/rcar-dmac.c +@@ -10,6 +10,7 @@ + * published by the Free Software Foundation. + */ + ++#include + #include + #include + #include +@@ -741,6 +742,24 @@ static int rcar_dmac_fill_hwdesc(struct rcar_dmac_chan *chan, + /* ----------------------------------------------------------------------------- + * Stop and reset + */ ++static void rcar_dmac_chcr_de_barrier(struct rcar_dmac_chan *chan) ++{ ++ u32 chcr; ++ unsigned int i; ++ ++ /* ++ * Ensure that the setting of the DE bit is actually 0 after ++ * clearing it. ++ */ ++ for (i = 0; i < 1024; i++) { ++ chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); ++ if (!(chcr & RCAR_DMACHCR_DE)) ++ return; ++ udelay(1); ++ } ++ ++ dev_err(chan->chan.device->dev, "CHCR DE check error\n"); ++} + + static void rcar_dmac_chan_halt(struct rcar_dmac_chan *chan) + { +@@ -749,6 +768,7 @@ static void rcar_dmac_chan_halt(struct rcar_dmac_chan *chan) + chcr &= ~(RCAR_DMACHCR_DSE | RCAR_DMACHCR_DSIE | RCAR_DMACHCR_IE | + RCAR_DMACHCR_TE | RCAR_DMACHCR_DE); + rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr); ++ rcar_dmac_chcr_de_barrier(chan); + } + + static void rcar_dmac_chan_reinit(struct rcar_dmac_chan *chan) +@@ -1481,6 +1501,8 @@ static irqreturn_t rcar_dmac_isr_channel(int irq, void *dev) + if (chcr & RCAR_DMACHCR_TE) + mask |= RCAR_DMACHCR_DE; + rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr & ~mask); ++ if (mask & RCAR_DMACHCR_DE) ++ rcar_dmac_chcr_de_barrier(chan); + + if (chcr & RCAR_DMACHCR_DSE) + ret |= rcar_dmac_isr_desc_stage_end(chan); +-- +1.9.1 + diff --git a/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0081-dmaengine-rcar-dmac-use-TCRB-instead-of-TCR-for-resi.patch b/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0081-dmaengine-rcar-dmac-use-TCRB-instead-of-TCR-for-resi.patch new file mode 100644 index 0000000..c9bfdfb --- /dev/null +++ b/meta-rcar-gen3-adas/recipes-kernel/linux/linux-renesas/0081-dmaengine-rcar-dmac-use-TCRB-instead-of-TCR-for-resi.patch @@ -0,0 +1,108 @@ +From 73a47bd0da668c99f04e9076f2b02101a5b2749b Mon Sep 17 00:00:00 2001 +From: Kuninori Morimoto +Date: Fri, 17 Nov 2017 02:09:32 +0000 +Subject: [PATCH 2/2] dmaengine: rcar-dmac: use TCRB instead of TCR for residue + +SYS/RT/Audio DMAC includes independent data buffers for reading +and writing. Therefore, the read transfer counter and write transfer +counter have different values. +TCR indicates read counter, and TCRB indicates write counter. +The relationship is like below. + + TCR TCRB + [SOURCE] -> [DMAC] -> [SINK] + +In the MEM_TO_DEV direction, what really matters is how much data has +been written to the device. If the DMA is interrupted between read and +write, then, the data doesn't end up in the destination, so shouldn't +be counted. TCRB is thus the register we should use in this cases. + +In the DEV_TO_MEM direction, the situation is more complex. Both the +read and write side are important. What matters from a data consumer +point of view is how much data has been written to memory. +On the other hand, if the transfer is interrupted between read and +write, we'll end up losing data. It can also be important to report. + +In the MEM_TO_MEM direction, what matters is of course how much data +has been written to memory from data consumer point of view. +Here, because read and write have independent data buffers, it will +take a while for TCR and TCRB to become equal. Thus we should check +TCRB in this case, too. + +Thus, all cases we should check TCRB instead of TCR. + +Without this patch, Sound Capture has noise after PulseAudio support +(= 07b7acb51d2 ("ASoC: rsnd: update pointer more accurate")), because +the recorder will use wrong residue counter which indicates transferred +from sound device, but in reality the data was not yet put to memory +and recorder will record it. + +However, because DMAC is buffering data until it can be transferable +size, TCRB might not be updated. +For example, if consumer doesn't know how much data can be received, +it requests enough size to DMAC. But in reality, it might receive very +few data. In such case, DMAC just buffered it until transferable size, +and no TCRB updated. + +In such case, this buffered data will be transferred if CHCR::DE bit was +cleared, and this is happen if rcar_dmac_chan_halt(). In other word, it +happen when consumer called dmaengine_terminate_all(). + +Because of this behavior, it need to flush buffered data when it returns +"residue" (= dmaengine_tx_status()). +Otherwise, consumer might calculate wrong things if it called +dmaengine_tx_status() and dmaengine_terminate_all() consecutively. + +Signed-off-by: Kuninori Morimoto +Tested-by: Hiroyuki Yokoyama +Tested-by: Ryo Kodama +Tested-by: Geert Uytterhoeven +Signed-off-by: Vinod Koul +--- + drivers/dma/sh/rcar-dmac.c | 22 +++++++++++++++++++++- + 1 file changed, 21 insertions(+), 1 deletion(-) + +diff --git a/drivers/dma/sh/rcar-dmac.c b/drivers/dma/sh/rcar-dmac.c +index c99fd0f..3bbd11d 100644 +--- a/drivers/dma/sh/rcar-dmac.c ++++ b/drivers/dma/sh/rcar-dmac.c +@@ -761,6 +761,23 @@ static void rcar_dmac_chcr_de_barrier(struct rcar_dmac_chan *chan) + dev_err(chan->chan.device->dev, "CHCR DE check error\n"); + } + ++static void rcar_dmac_sync_tcr(struct rcar_dmac_chan *chan) ++{ ++ u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); ++ ++ if (!(chcr & RCAR_DMACHCR_DE)) ++ return; ++ ++ /* set DE=0 and flush remaining data */ ++ rcar_dmac_chan_write(chan, RCAR_DMACHCR, (chcr & ~RCAR_DMACHCR_DE)); ++ ++ /* make sure all remaining data was flushed */ ++ rcar_dmac_chcr_de_barrier(chan); ++ ++ /* back DE */ ++ rcar_dmac_chan_write(chan, RCAR_DMACHCR, chcr); ++} ++ + static void rcar_dmac_chan_halt(struct rcar_dmac_chan *chan) + { + u32 chcr = rcar_dmac_chan_read(chan, RCAR_DMACHCR); +@@ -1329,8 +1346,11 @@ static unsigned int rcar_dmac_chan_get_residue(struct rcar_dmac_chan *chan, + residue += chunk->size; + } + ++ if (desc->direction == DMA_DEV_TO_MEM) ++ rcar_dmac_sync_tcr(chan); ++ + /* Add the residue for the current chunk. */ +- residue += rcar_dmac_chan_read(chan, RCAR_DMATCR) << desc->xfer_shift; ++ residue += rcar_dmac_chan_read(chan, RCAR_DMATCRB) << desc->xfer_shift; + + return residue; + } +-- +1.9.1 + -- cgit 1.2.3-korg