dma: shdma: fix runtime PM: clear channel buffers on reset
On platforms, supporting power domains, if the domain, containing a DMAC
instance is powered down, the driver fails to resume correctly. On those
platforms DMAC channels have an additional CHCLR register for clearing
channel buffers. Using this register during runtime resume fixes the
problem.
Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
diff --git a/drivers/dma/shdma.c b/drivers/dma/shdma.c
index 592304f..54043cd 100644
--- a/drivers/dma/shdma.c
+++ b/drivers/dma/shdma.c
@@ -56,6 +56,15 @@
static unsigned long sh_dmae_slave_used[BITS_TO_LONGS(SH_DMA_SLAVE_NUMBER)];
static void sh_dmae_chan_ld_cleanup(struct sh_dmae_chan *sh_chan, bool all);
+static void sh_chan_xfer_ld_queue(struct sh_dmae_chan *sh_chan);
+
+static void chclr_write(struct sh_dmae_chan *sh_dc, u32 data)
+{
+ struct sh_dmae_device *shdev = to_sh_dev(sh_dc);
+
+ __raw_writel(data, shdev->chan_reg +
+ shdev->pdata->channel[sh_dc->id].chclr_offset);
+}
static void sh_dmae_writel(struct sh_dmae_chan *sh_dc, u32 data, u32 reg)
{
@@ -128,6 +137,15 @@
dmaor = dmaor_read(shdev) & ~(DMAOR_NMIF | DMAOR_AE | DMAOR_DME);
+ if (shdev->pdata->chclr_present) {
+ int i;
+ for (i = 0; i < shdev->pdata->channel_num; i++) {
+ struct sh_dmae_chan *sh_chan = shdev->chan[i];
+ if (sh_chan)
+ chclr_write(sh_chan, 0);
+ }
+ }
+
dmaor_write(shdev, dmaor | shdev->pdata->dmaor_init);
dmaor = dmaor_read(shdev);
@@ -138,6 +156,10 @@
dev_warn(shdev->common.dev, "Can't initialize DMAOR.\n");
return -EIO;
}
+ if (shdev->pdata->dmaor_init & ~dmaor)
+ dev_warn(shdev->common.dev,
+ "DMAOR=0x%x hasn't latched the initial value 0x%x.\n",
+ dmaor, shdev->pdata->dmaor_init);
return 0;
}
@@ -258,8 +280,6 @@
return 0;
}
-static void sh_chan_xfer_ld_queue(struct sh_dmae_chan *sh_chan);
-
static dma_cookie_t sh_dmae_tx_submit(struct dma_async_tx_descriptor *tx)
{
struct sh_desc *desc = tx_to_sh_desc(tx), *chunk, *last = desc, *c;
@@ -339,6 +359,8 @@
sh_chan_xfer_ld_queue(sh_chan);
sh_chan->pm_state = DMAE_PM_ESTABLISHED;
}
+ } else {
+ sh_chan->pm_state = DMAE_PM_PENDING;
}
spin_unlock_irq(&sh_chan->desc_lock);
@@ -1224,6 +1246,8 @@
platform_set_drvdata(pdev, shdev);
+ shdev->common.dev = &pdev->dev;
+
pm_runtime_enable(&pdev->dev);
pm_runtime_get_sync(&pdev->dev);
@@ -1253,7 +1277,6 @@
shdev->common.device_prep_slave_sg = sh_dmae_prep_slave_sg;
shdev->common.device_control = sh_dmae_control;
- shdev->common.dev = &pdev->dev;
/* Default transfer size of 32 bytes requires 32-byte alignment */
shdev->common.copy_align = LOG2_DEFAULT_XFER_SIZE;
@@ -1434,22 +1457,17 @@
#ifdef CONFIG_PM
static int sh_dmae_suspend(struct device *dev)
{
- struct sh_dmae_device *shdev = dev_get_drvdata(dev);
- int i;
-
- for (i = 0; i < shdev->pdata->channel_num; i++) {
- struct sh_dmae_chan *sh_chan = shdev->chan[i];
- if (sh_chan->descs_allocated)
- sh_chan->pm_error = pm_runtime_put_sync(dev);
- }
-
return 0;
}
static int sh_dmae_resume(struct device *dev)
{
struct sh_dmae_device *shdev = dev_get_drvdata(dev);
- int i;
+ int i, ret;
+
+ ret = sh_dmae_rst(shdev);
+ if (ret < 0)
+ dev_err(dev, "Failed to reset!\n");
for (i = 0; i < shdev->pdata->channel_num; i++) {
struct sh_dmae_chan *sh_chan = shdev->chan[i];
@@ -1458,9 +1476,6 @@
if (!sh_chan->descs_allocated)
continue;
- if (!sh_chan->pm_error)
- pm_runtime_get_sync(dev);
-
if (param) {
const struct sh_dmae_slave_config *cfg = param->config;
dmae_set_dmars(sh_chan, cfg->mid_rid);