[PATCH 4/4] dmaengine: stm32-mdma: rework interrupt handler

From: Amelie Delaunay
Date: Fri Nov 20 2020 - 09:34:06 EST


To avoid multiple entries in MDMA interrupt handler for each flag&interrupt
enable, manage all flags set at once.

Signed-off-by: Amelie Delaunay <amelie.delaunay@xxxxxx>
---
drivers/dma/stm32-mdma.c | 64 +++++++++++++++++++++-------------------
1 file changed, 34 insertions(+), 30 deletions(-)

diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c
index 29e5e30524bb..e4637ec786d3 100644
--- a/drivers/dma/stm32-mdma.c
+++ b/drivers/dma/stm32-mdma.c
@@ -1346,7 +1346,7 @@ static irqreturn_t stm32_mdma_irq_handler(int irq, void *devid)
{
struct stm32_mdma_device *dmadev = devid;
struct stm32_mdma_chan *chan = devid;
- u32 reg, id, ien, status, flag;
+ u32 reg, id, ccr, ien, status;

/* Find out which channel generates the interrupt */
status = readl_relaxed(dmadev->base + STM32_MDMA_GISR0);
@@ -1368,67 +1368,71 @@ static irqreturn_t stm32_mdma_irq_handler(int irq, void *devid)

chan = &dmadev->chan[id];
if (!chan) {
- dev_dbg(mdma2dev(dmadev), "MDMA channel not initialized\n");
- goto exit;
+ dev_warn(mdma2dev(dmadev), "MDMA channel not initialized\n");
+ return IRQ_NONE;
}

/* Handle interrupt for the channel */
spin_lock(&chan->vchan.lock);
- status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(chan->id));
- ien = stm32_mdma_read(dmadev, STM32_MDMA_CCR(chan->id));
- ien &= STM32_MDMA_CCR_IRQ_MASK;
- ien >>= 1;
+ status = stm32_mdma_read(dmadev, STM32_MDMA_CISR(id));
+ /* Mask Channel ReQuest Active bit which can be set in case of MEM2MEM */
+ status &= ~STM32_MDMA_CISR_CRQA;
+ ccr = stm32_mdma_read(dmadev, STM32_MDMA_CCR(id));
+ ien = (ccr & STM32_MDMA_CCR_IRQ_MASK) >> 1;

if (!(status & ien)) {
spin_unlock(&chan->vchan.lock);
- dev_dbg(chan2dev(chan),
- "spurious it (status=0x%04x, ien=0x%04x)\n",
- status, ien);
+ dev_warn(chan2dev(chan),
+ "spurious it (status=0x%04x, ien=0x%04x)\n",
+ status, ien);
return IRQ_NONE;
}

- flag = __ffs(status & ien);
- reg = STM32_MDMA_CIFCR(chan->id);
+ reg = STM32_MDMA_CIFCR(id);

- switch (1 << flag) {
- case STM32_MDMA_CISR_TEIF:
- id = chan->id;
- status = readl_relaxed(dmadev->base + STM32_MDMA_CESR(id));
- dev_err(chan2dev(chan), "Transfer Err: stat=0x%08x\n", status);
+ if (status & STM32_MDMA_CISR_TEIF) {
+ dev_err(chan2dev(chan), "Transfer Err: stat=0x%08x\n",
+ readl_relaxed(dmadev->base + STM32_MDMA_CESR(id)));
stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CTEIF);
- break;
+ status &= ~STM32_MDMA_CISR_TEIF;
+ }

- case STM32_MDMA_CISR_CTCIF:
+ if (status & STM32_MDMA_CISR_CTCIF) {
stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CCTCIF);
+ status &= ~STM32_MDMA_CISR_CTCIF;
stm32_mdma_xfer_end(chan);
- break;
+ }

- case STM32_MDMA_CISR_BRTIF:
+ if (status & STM32_MDMA_CISR_BRTIF) {
stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CBRTIF);
- break;
+ status &= ~STM32_MDMA_CISR_BRTIF;
+ }

- case STM32_MDMA_CISR_BTIF:
+ if (status & STM32_MDMA_CISR_BTIF) {
stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CBTIF);
+ status &= ~STM32_MDMA_CISR_BTIF;
chan->curr_hwdesc++;
if (chan->desc && chan->desc->cyclic) {
if (chan->curr_hwdesc == chan->desc->count)
chan->curr_hwdesc = 0;
vchan_cyclic_callback(&chan->desc->vdesc);
}
- break;
+ }

- case STM32_MDMA_CISR_TCIF:
+ if (status & STM32_MDMA_CISR_TCIF) {
stm32_mdma_set_bits(dmadev, reg, STM32_MDMA_CIFCR_CLTCIF);
- break;
+ status &= ~STM32_MDMA_CISR_TCIF;
+ }

- default:
- dev_err(chan2dev(chan), "it %d unhandled (status=0x%04x)\n",
- 1 << flag, status);
+ if (status) {
+ stm32_mdma_set_bits(dmadev, reg, status);
+ dev_err(chan2dev(chan), "DMA error: status=0x%08x\n", status);
+ if (!(ccr & STM32_MDMA_CCR_EN))
+ dev_err(chan2dev(chan), "chan disabled by HW\n");
}

spin_unlock(&chan->vchan.lock);

-exit:
return IRQ_HANDLED;
}

--
2.17.1