Return probe defer if requesting a dma channel without a dma controller probed.
Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>
---
drivers/i2c/busses/i2c-at91.c | 22 ++++++++++++++++------
1 file changed, 16 insertions(+), 6 deletions(-)
diff --git a/drivers/i2c/busses/i2c-at91.c b/drivers/i2c/busses/i2c-at91.c
index 77fb647..df3f4c4 100644
--- a/drivers/i2c/busses/i2c-at91.c
+++ b/drivers/i2c/busses/i2c-at91.c
@@ -679,14 +679,21 @@ static int at91_twi_configure_dma(struct at91_twi_dev *dev, u32 phy_addr)
dma_cap_zero(mask);
dma_cap_set(DMA_SLAVE, mask);
- dma->chan_tx = dma_request_slave_channel_compat(mask, filter, pdata,
- dev->dev, "tx");
- if (!dma->chan_tx) {
+ dma->chan_tx = dma_request_slave_channel_reason(dev->dev, "tx");
+ if (IS_ERR(dma->chan_tx)) {
+ ret = PTR_ERR(dma->chan_tx);
+ if (ret == -EPROBE_DEFER) {
+ dev_warn(dev->dev, "no DMA channel available at the moment\n");
+ return ret;
+ }
dev_err(dev->dev, "can't get a DMA channel for tx\n");
- ret = -EBUSY;
goto error;
}
+ /*
+ * No reason to check EPROBE_DEFER here since we have already request
+ * tx channel. If it fails here, it's for another reason.
+ */
dma->chan_rx = dma_request_slave_channel_compat(mask, filter, pdata,
dev->dev, "rx");
if (!dma->chan_rx) {
@@ -722,7 +729,7 @@ error:
dev_info(dev->dev, "can't use DMA\n");
if (dma->chan_rx)
dma_release_channel(dma->chan_rx);
- if (dma->chan_tx)
+ if (!IS_ERR(dma->chan_tx))
dma_release_channel(dma->chan_tx);
return ret;
}
@@ -788,8 +795,11 @@ static int at91_twi_probe(struct platform_device *pdev)
clk_prepare_enable(dev->clk);
if (dev->pdata->has_dma_support) {
- if (at91_twi_configure_dma(dev, phy_addr) == 0)
+ rc = at91_twi_configure_dma(dev, phy_addr);
+ if (rc == 0)
dev->use_dma = true;
+ else if (rc == -EPROBE_DEFER)
+ return rc;
}
rc = of_property_read_u32(dev->dev->of_node, "clock-frequency",
--
2.0.3
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