When a channel is configured to suppress host side interrupts (RIE=0), the host side driver cannot rely on IRQ-driven progress. Add an optional polling path for such channels. Polling is only enabled for channels where dw_edma_chan_ignore_irq() is true.
Signed-off-by: Koichiro Den <[email protected]> --- drivers/dma/dw-edma/dw-edma-core.c | 98 ++++++++++++++++++++++++------ drivers/dma/dw-edma/dw-edma-core.h | 4 ++ 2 files changed, 85 insertions(+), 17 deletions(-) diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c index 059b3996d383..696b9f3ea378 100644 --- a/drivers/dma/dw-edma/dw-edma-core.c +++ b/drivers/dma/dw-edma/dw-edma-core.c @@ -308,23 +308,6 @@ static int dw_edma_device_terminate_all(struct dma_chan *dchan) return err; } -static void dw_edma_device_issue_pending(struct dma_chan *dchan) -{ - struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); - unsigned long flags; - - if (!chan->configured) - return; - - spin_lock_irqsave(&chan->vc.lock, flags); - if (vchan_issue_pending(&chan->vc) && chan->request == EDMA_REQ_NONE && - chan->status == EDMA_ST_IDLE) { - chan->status = EDMA_ST_BUSY; - dw_edma_start_transfer(chan); - } - spin_unlock_irqrestore(&chan->vc.lock, flags); -} - static enum dma_status dw_edma_device_tx_status(struct dma_chan *dchan, dma_cookie_t cookie, struct dma_tx_state *txstate) @@ -710,6 +693,69 @@ static irqreturn_t dw_edma_interrupt_common(int irq, void *data) return ret; } +static void dw_edma_done_arm(struct dw_edma_chan *chan) +{ + if (!dw_edma_chan_ignore_irq(&chan->vc.chan)) + /* no need to arm since it's not to be ignored */ + return; + + queue_delayed_work(system_wq, &chan->poll_work, 1); +} + +static void dw_edma_chan_poll_done(struct dma_chan *dchan) +{ + struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); + enum dma_status st; + + if (!dw_edma_chan_ignore_irq(dchan)) + /* no need to poll since it's not to be ignored */ + return; + + guard(spinlock_irqsave)(&chan->poll_lock); + + if (chan->status != EDMA_ST_BUSY) + return; + + st = dw_edma_core_ch_status(chan); + + switch (st) { + case DMA_COMPLETE: + dw_edma_done_interrupt(chan); + if (chan->status == EDMA_ST_BUSY) + dw_edma_done_arm(chan); + break; + case DMA_IN_PROGRESS: + dw_edma_done_arm(chan); + break; + case DMA_ERROR: + dw_edma_abort_interrupt(chan); + break; + default: + break; + } +} + +static void dw_edma_device_issue_pending(struct dma_chan *dchan) +{ + struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); + unsigned long flags; + + if (!chan->configured) + return; + + dw_edma_chan_poll_done(dchan); + + spin_lock_irqsave(&chan->vc.lock, flags); + if (vchan_issue_pending(&chan->vc) && chan->request == EDMA_REQ_NONE && + chan->status == EDMA_ST_IDLE) { + chan->status = EDMA_ST_BUSY; + dw_edma_start_transfer(chan); + } else { + dw_edma_done_arm(chan); + } + spin_unlock_irqrestore(&chan->vc.lock, flags); +} + static int dw_edma_alloc_chan_resources(struct dma_chan *dchan) { struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan); @@ -1063,6 +1109,19 @@ int dw_edma_remove(struct dw_edma_chip *chip) } EXPORT_SYMBOL_GPL(dw_edma_remove); +static void dw_edma_poll_work(struct work_struct *work) +{ + struct delayed_work *dwork = to_delayed_work(work); + struct dw_edma_chan *chan = + container_of(dwork, struct dw_edma_chan, poll_work); + struct dma_chan *dchan = &chan->vc.chan; + + if (!chan->configured) + return; + + dw_edma_chan_poll_done(dchan); +} + int dw_edma_chan_irq_config(struct dma_chan *dchan, enum dw_edma_ch_irq_mode mode) { @@ -1090,6 +1149,11 @@ int dw_edma_chan_irq_config(struct dma_chan *dchan, str_write_read(chan->dir == EDMA_DIR_WRITE), chan->id, mode); + if (dw_edma_chan_ignore_irq(&chan->vc.chan)) { + spin_lock_init(&chan->poll_lock); + INIT_DELAYED_WORK(&chan->poll_work, dw_edma_poll_work); + } + return 0; } EXPORT_SYMBOL_GPL(dw_edma_chan_irq_config); diff --git a/drivers/dma/dw-edma/dw-edma-core.h b/drivers/dma/dw-edma/dw-edma-core.h index 8458d676551a..11fe4532f0bf 100644 --- a/drivers/dma/dw-edma/dw-edma-core.h +++ b/drivers/dma/dw-edma/dw-edma-core.h @@ -11,6 +11,7 @@ #include <linux/msi.h> #include <linux/dma/edma.h> +#include <linux/workqueue.h> #include "../virt-dma.h" @@ -83,6 +84,9 @@ struct dw_edma_chan { enum dw_edma_ch_irq_mode irq_mode; + struct delayed_work poll_work; + spinlock_t poll_lock; + enum dw_edma_request request; enum dw_edma_status status; u8 configured; -- 2.51.0
