dma: imx-sdma: make channel0 operations atomic
device_prep_dma_cyclic may be call in audio trigger function which is atomic context, so we make it atomic too. - change channel0 lock to spinlock. - Use polling to wait for channel0 finish running. 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>hifive-unleashed-5.1
Richard Zhao
Vinod Koul
parent
922ee08baa
commit
2ccaef0520
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@ -24,7 +24,7 @@
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#include <linux/mm.h>
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#include <linux/interrupt.h>
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#include <linux/clk.h>
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#include <linux/wait.h>
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#include <linux/delay.h>
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#include <linux/sched.h>
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#include <linux/semaphore.h>
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#include <linux/spinlock.h>
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@ -324,7 +324,7 @@ struct sdma_engine {
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dma_addr_t context_phys;
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struct dma_device dma_device;
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struct clk *clk;
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struct mutex channel_0_lock;
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spinlock_t channel_0_lock;
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struct sdma_script_start_addrs *script_addrs;
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};
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@ -402,19 +402,27 @@ static void sdma_enable_channel(struct sdma_engine *sdma, int channel)
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}
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/*
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* sdma_run_channel - run a channel and wait till it's done
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* sdma_run_channel0 - run a channel and wait till it's done
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*/
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static int sdma_run_channel(struct sdma_channel *sdmac)
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static int sdma_run_channel0(struct sdma_engine *sdma)
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{
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struct sdma_engine *sdma = sdmac->sdma;
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int channel = sdmac->channel;
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int ret;
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unsigned long timeout = 500;
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init_completion(&sdmac->done);
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sdma_enable_channel(sdma, 0);
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sdma_enable_channel(sdma, channel);
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while (!(ret = readl_relaxed(sdma->regs + SDMA_H_INTR) & 1)) {
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if (timeout-- <= 0)
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break;
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udelay(1);
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}
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ret = wait_for_completion_timeout(&sdmac->done, HZ);
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if (ret) {
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/* Clear the interrupt status */
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writel_relaxed(ret, sdma->regs + SDMA_H_INTR);
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} else {
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dev_err(sdma->dev, "Timeout waiting for CH0 ready\n");
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}
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return ret ? 0 : -ETIMEDOUT;
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}
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@ -426,17 +434,17 @@ static int sdma_load_script(struct sdma_engine *sdma, void *buf, int size,
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void *buf_virt;
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dma_addr_t buf_phys;
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int ret;
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mutex_lock(&sdma->channel_0_lock);
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unsigned long flags;
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buf_virt = dma_alloc_coherent(NULL,
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size,
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&buf_phys, GFP_KERNEL);
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if (!buf_virt) {
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ret = -ENOMEM;
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goto err_out;
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return -ENOMEM;
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}
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spin_lock_irqsave(&sdma->channel_0_lock, flags);
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bd0->mode.command = C0_SETPM;
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bd0->mode.status = BD_DONE | BD_INTR | BD_WRAP | BD_EXTD;
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bd0->mode.count = size / 2;
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@ -445,13 +453,12 @@ static int sdma_load_script(struct sdma_engine *sdma, void *buf, int size,
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memcpy(buf_virt, buf, size);
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ret = sdma_run_channel(&sdma->channel[0]);
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ret = sdma_run_channel0(sdma);
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spin_unlock_irqrestore(&sdma->channel_0_lock, flags);
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dma_free_coherent(NULL, size, buf_virt, buf_phys);
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err_out:
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mutex_unlock(&sdma->channel_0_lock);
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return ret;
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}
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@ -541,10 +548,6 @@ static void sdma_tasklet(unsigned long data)
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complete(&sdmac->done);
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/* not interested in channel 0 interrupts */
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if (sdmac->channel == 0)
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return;
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if (sdmac->flags & IMX_DMA_SG_LOOP)
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sdma_handle_channel_loop(sdmac);
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else
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@ -557,6 +560,8 @@ static irqreturn_t sdma_int_handler(int irq, void *dev_id)
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unsigned long stat;
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stat = readl_relaxed(sdma->regs + SDMA_H_INTR);
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/* not interested in channel 0 interrupts */
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stat &= ~1;
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writel_relaxed(stat, sdma->regs + SDMA_H_INTR);
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while (stat) {
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@ -662,6 +667,7 @@ static int sdma_load_context(struct sdma_channel *sdmac)
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struct sdma_context_data *context = sdma->context;
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struct sdma_buffer_descriptor *bd0 = sdma->channel[0].bd;
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int ret;
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unsigned long flags;
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if (sdmac->direction == DMA_DEV_TO_MEM) {
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load_address = sdmac->pc_from_device;
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@ -679,7 +685,7 @@ static int sdma_load_context(struct sdma_channel *sdmac)
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dev_dbg(sdma->dev, "event_mask0 = 0x%08x\n", (u32)sdmac->event_mask[0]);
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dev_dbg(sdma->dev, "event_mask1 = 0x%08x\n", (u32)sdmac->event_mask[1]);
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mutex_lock(&sdma->channel_0_lock);
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spin_lock_irqsave(&sdma->channel_0_lock, flags);
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memset(context, 0, sizeof(*context));
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context->channel_state.pc = load_address;
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@ -698,10 +704,9 @@ static int sdma_load_context(struct sdma_channel *sdmac)
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bd0->mode.count = sizeof(*context) / 4;
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bd0->buffer_addr = sdma->context_phys;
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bd0->ext_buffer_addr = 2048 + (sizeof(*context) / 4) * channel;
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ret = sdma_run_channel0(sdma);
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ret = sdma_run_channel(&sdma->channel[0]);
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mutex_unlock(&sdma->channel_0_lock);
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spin_unlock_irqrestore(&sdma->channel_0_lock, flags);
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return ret;
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}
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@ -1300,7 +1305,7 @@ static int __init sdma_probe(struct platform_device *pdev)
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if (!sdma)
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return -ENOMEM;
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mutex_init(&sdma->channel_0_lock);
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spin_lock_init(&sdma->channel_0_lock);
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sdma->dev = &pdev->dev;
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