From: Akhil R <akhilrajeev@nvidia.com>

Currently, the driver does not return the correct DMA status when a DMA
pause is issued by the client drivers. This causes GPCDMA users to
assume that DMA is still running, while in reality, the DMA is paused.

Return DMA_PAUSED for tx_status() if the channel is paused in the middle
of a transfer.

Fixes: ee17028009d4 ("dmaengine: tegra: Add tegra gpcdma driver")
Cc: stable@vger.kernel.org
Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Signed-off-by: Kartik Rajput <kkartik@nvidia.com>
---
 drivers/dma/tegra186-gpc-dma.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/dma/tegra186-gpc-dma.c b/drivers/dma/tegra186-gpc-dma.c
index cacf3757adc2..4d6fe0efa76e 100644
--- a/drivers/dma/tegra186-gpc-dma.c
+++ b/drivers/dma/tegra186-gpc-dma.c
@@ -231,6 +231,7 @@ struct tegra_dma_channel {
 	bool config_init;
 	char name[30];
 	enum dma_transfer_direction sid_dir;
+	enum dma_status status;
 	int id;
 	int irq;
 	int slave_id;
@@ -393,6 +394,8 @@ static int tegra_dma_pause(struct tegra_dma_channel *tdc)
 		tegra_dma_dump_chan_regs(tdc);
 	}
 
+	tdc->status = DMA_PAUSED;
+
 	return ret;
 }
 
@@ -419,6 +422,8 @@ static void tegra_dma_resume(struct tegra_dma_channel *tdc)
 	val = tdc_read(tdc, TEGRA_GPCDMA_CHAN_CSRE);
 	val &= ~TEGRA_GPCDMA_CHAN_CSRE_PAUSE;
 	tdc_write(tdc, TEGRA_GPCDMA_CHAN_CSRE, val);
+
+	tdc->status = DMA_IN_PROGRESS;
 }
 
 static int tegra_dma_device_resume(struct dma_chan *dc)
@@ -544,6 +549,7 @@ static void tegra_dma_xfer_complete(struct tegra_dma_channel *tdc)
 
 	tegra_dma_sid_free(tdc);
 	tdc->dma_desc = NULL;
+	tdc->status = DMA_COMPLETE;
 }
 
 static void tegra_dma_chan_decode_error(struct tegra_dma_channel *tdc,
@@ -716,6 +722,7 @@ static int tegra_dma_terminate_all(struct dma_chan *dc)
 		tdc->dma_desc = NULL;
 	}
 
+	tdc->status = DMA_COMPLETE;
 	tegra_dma_sid_free(tdc);
 	vchan_get_all_descriptors(&tdc->vc, &head);
 	spin_unlock_irqrestore(&tdc->vc.lock, flags);
@@ -769,6 +776,9 @@ static enum dma_status tegra_dma_tx_status(struct dma_chan *dc,
 	if (ret == DMA_COMPLETE)
 		return ret;
 
+	if (tdc->status == DMA_PAUSED)
+		ret = DMA_PAUSED;
+
 	spin_lock_irqsave(&tdc->vc.lock, flags);
 	vd = vchan_find_desc(&tdc->vc, cookie);
 	if (vd) {
-- 
2.47.0

On Thu, 12 Dec 2024 18:14:12 +0530, Kartik Rajput wrote:
> Currently, the driver does not return the correct DMA status when a DMA
> pause is issued by the client drivers. This causes GPCDMA users to
> assume that DMA is still running, while in reality, the DMA is paused.
> 
> Return DMA_PAUSED for tx_status() if the channel is paused in the middle
> of a transfer.
> 
> [...]

Applied, thanks!

[1/1] dmaengine: tegra: Return correct DMA status when paused
      commit: ebc008699fd95701c9af5ebaeb0793eef81a71d5

Best regards,
-- 
~Vinod