[PATCH -next 2/4] dmaengine: xilinx_dma: Fix control reg update in vdma_channel_set_config

From: Radhey Shyam Pandey
Date: Thu Sep 26 2019 - 06:51:37 EST


In vdma_channel_set_config clear the delay, frame count and master mask
before updating their new values. It avoids programming incorrect state
when input parameters are different from default.

Signed-off-by: Radhey Shyam Pandey <radhey.shyam.pandey@xxxxxxxxxx>
Acked-by: Appana Durga Kedareswara rao <appana.durga.rao@xxxxxxxxxx>
Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
---
drivers/dma/xilinx/xilinx_dma.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 1fbe025..5d56f1e 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -68,6 +68,9 @@
#define XILINX_DMA_DMACR_CIRC_EN BIT(1)
#define XILINX_DMA_DMACR_RUNSTOP BIT(0)
#define XILINX_DMA_DMACR_FSYNCSRC_MASK GENMASK(6, 5)
+#define XILINX_DMA_DMACR_DELAY_MASK GENMASK(31, 24)
+#define XILINX_DMA_DMACR_FRAME_COUNT_MASK GENMASK(23, 16)
+#define XILINX_DMA_DMACR_MASTER_MASK GENMASK(11, 8)

#define XILINX_DMA_REG_DMASR 0x0004
#define XILINX_DMA_DMASR_EOL_LATE_ERR BIT(15)
@@ -2118,8 +2121,10 @@ int xilinx_vdma_channel_set_config(struct dma_chan *dchan,
chan->config.gen_lock = cfg->gen_lock;
chan->config.master = cfg->master;

+ dmacr &= ~XILINX_DMA_DMACR_GENLOCK_EN;
if (cfg->gen_lock && chan->genlock) {
dmacr |= XILINX_DMA_DMACR_GENLOCK_EN;
+ dmacr &= ~XILINX_DMA_DMACR_MASTER_MASK;
dmacr |= cfg->master << XILINX_DMA_DMACR_MASTER_SHIFT;
}

@@ -2135,11 +2140,13 @@ int xilinx_vdma_channel_set_config(struct dma_chan *dchan,
chan->config.delay = cfg->delay;

if (cfg->coalesc <= XILINX_DMA_DMACR_FRAME_COUNT_MAX) {
+ dmacr &= ~XILINX_DMA_DMACR_FRAME_COUNT_MASK;
dmacr |= cfg->coalesc << XILINX_DMA_DMACR_FRAME_COUNT_SHIFT;
chan->config.coalesc = cfg->coalesc;
}

if (cfg->delay <= XILINX_DMA_DMACR_DELAY_MAX) {
+ dmacr &= ~XILINX_DMA_DMACR_DELAY_MASK;
dmacr |= cfg->delay << XILINX_DMA_DMACR_DELAY_SHIFT;
chan->config.delay = cfg->delay;
}
--
1.7.1