6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tze Yee Ng [ Upstream commit df0c2dc68770cf43f15df40b184df030b850ea05 ] The driver only had runtime PM callbacks. If a channel stayed allocated across system suspend/resume, the runtime usage count could remain non-zero while hardware state (DMAC_CFG, clocks) was lost, and axi_dma_runtime_resume() would not run to restore it. Add system-sleep PM ops that use pm_runtime_force_suspend() and pm_runtime_force_resume() so suspend/resume reuses the existing axi_dma_suspend() and axi_dma_resume() paths. Replace pm_runtime_get() with pm_runtime_resume_and_get() in dma_chan_alloc_chan_resources() so clocks are enabled before a client can immediately submit a transfer and touch MMIO. Signed-off-by: Tze Yee Ng Link: https://patch.msgid.link/18bf778a3a1cc2f377ef8eb0d1508d8ac6371896.1779688569.git.tze.yee.ng@altera.com Signed-off-by: Vinod Koul Signed-off-by: Sasha Levin --- drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c index 3ea3e203253a9..3152c8b52884c 100644 --- a/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c +++ b/drivers/dma/dw-axi-dmac/dw-axi-dmac-platform.c @@ -470,11 +470,17 @@ static void dw_axi_dma_synchronize(struct dma_chan *dchan) static int dma_chan_alloc_chan_resources(struct dma_chan *dchan) { struct axi_dma_chan *chan = dchan_to_axi_dma_chan(dchan); + int ret; + + ret = pm_runtime_resume_and_get(chan->chip->dev); + if (ret < 0) + return ret; /* ASSERT: channel is idle */ if (axi_chan_is_hw_enable(chan)) { dev_err(chan2dev(chan), "%s is non-idle!\n", axi_chan_name(chan)); + pm_runtime_put(chan->chip->dev); return -EBUSY; } @@ -485,12 +491,11 @@ static int dma_chan_alloc_chan_resources(struct dma_chan *dchan) 64, 0); if (!chan->desc_pool) { dev_err(chan2dev(chan), "No memory for descriptors\n"); + pm_runtime_put(chan->chip->dev); return -ENOMEM; } dev_vdbg(dchan2dev(dchan), "%s: allocating\n", axi_chan_name(chan)); - pm_runtime_get(chan->chip->dev); - return 0; } @@ -1565,6 +1570,8 @@ static int dw_remove(struct platform_device *pdev) } static const struct dev_pm_ops dw_axi_dma_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, + pm_runtime_force_resume) SET_RUNTIME_PM_OPS(axi_dma_runtime_suspend, axi_dma_runtime_resume, NULL) }; -- 2.53.0