[PATCH v2] Revert "dmaengine: dw: Enable runtime PM"

[PATCH v2] Revert "dmaengine: dw: Enable runtime PM"

[Cezary Rojewski]

This reverts commit 842067940a3e3fc008a60fee388e000219b32632.
For some solutions e.g. sound/soc/intel/catpt, DW DMA is part of a
compound device (in that very example, domains: ADSP, SSP0, SSP1, DMA0
and DMA1 are part of a single entity) rather than being a standalone
one. Driver for said device may enlist DMA to transfer data during
suspend or resume sequences.

Manipulating RPM explicitly in dw's DMA request and release channel
functions causes suspend() to also invoke resume() for the exact same
device. Similar situation occurs for resume() sequence. Effectively
renders device dysfunctional after first suspend() attempt. Revert the
change to address the problem.

Fixes: 842067940a3e ("dmaengine: dw: Enable runtime PM")
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Cezary Rojewski <cezary.rojewski@intel.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
---

Changes v2:
- enriched tag area with fixes tag

 drivers/dma/dw/core.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index 19a23767533a..7ab83fe601ed 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -982,11 +982,8 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
 
 	dev_vdbg(chan2dev(chan), "%s\n", __func__);
 
-	pm_runtime_get_sync(dw->dma.dev);
-
 	/* ASSERT:  channel is idle */
 	if (dma_readl(dw, CH_EN) & dwc->mask) {
-		pm_runtime_put_sync_suspend(dw->dma.dev);
 		dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
 		return -EIO;
 	}
@@ -1003,7 +1000,6 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan)
 	 * We need controller-specific data to set up slave transfers.
 	 */
 	if (chan->private && !dw_dma_filter(chan, chan->private)) {
-		pm_runtime_put_sync_suspend(dw->dma.dev);
 		dev_warn(chan2dev(chan), "Wrong controller-specific data\n");
 		return -EINVAL;
 	}
@@ -1047,8 +1043,6 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
 	if (!dw->in_use)
 		do_dw_dma_off(dw);
 
-	pm_runtime_put_sync_suspend(dw->dma.dev);
-
 	dev_vdbg(chan2dev(chan), "%s: done\n", __func__);
 }
 
-- 
2.17.1

Re: [PATCH v2] Revert "dmaengine: dw: Enable runtime PM"

[Vinod Koul]

On 03-02-21, 20:19, Cezary Rojewski wrote:
> This reverts commit 842067940a3e3fc008a60fee388e000219b32632.
> For some solutions e.g. sound/soc/intel/catpt, DW DMA is part of a
> compound device (in that very example, domains: ADSP, SSP0, SSP1, DMA0
> and DMA1 are part of a single entity) rather than being a standalone
> one. Driver for said device may enlist DMA to transfer data during
> suspend or resume sequences.
> 
> Manipulating RPM explicitly in dw's DMA request and release channel
> functions causes suspend() to also invoke resume() for the exact same
> device. Similar situation occurs for resume() sequence. Effectively
> renders device dysfunctional after first suspend() attempt. Revert the
> change to address the problem.

Reverts also need proper tagging, so pls ensure that is done. I have
added the subsystem and driver tags and applied

-- 
~Vinod