Having no DMA devices registered is not a guarantee that the device
doesn't exist, it could be that is not registered yet, so return
EPROBE_DEFER unconditionally so the caller can wait for the required
DMA device registered.
Signed-off-by: Enric Balletbo i Serra <eballetb@xxxxxxxxxx>
---
This patch fixes the following error on TI AM69-SK
[ 2.854501] cadence-qspi 47040000.spi: error -ENODEV: No Rx DMA available
The DMA device is probed after cadence-qspi driver, so deferring it
solves the problem.
---
drivers/dma/dmaengine.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index c1357d7f3dc6ca7899c4d68a039567e73b0f089d..57f07b477a5d9ad8f2656584b8c0d6dffb2ab469 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -889,10 +889,10 @@ struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask)
chan = __dma_request_channel(mask, NULL, NULL, NULL);
if (!chan) {
mutex_lock(&dma_list_mutex);
- if (list_empty(&dma_device_list))
- chan = ERR_PTR(-EPROBE_DEFER);
- else
- chan = ERR_PTR(-ENODEV);
+ /* If the required DMA device is not registered yet,
+ * return EPROBE_DEFER
+ */
+ chan = ERR_PTR(-EPROBE_DEFER);
mutex_unlock(&dma_list_mutex);
}
---
base-commit: 43fb83c17ba2d63dfb798f0be7453ed55ca3f9c2
change-id: 20241127-defer-dma-request-chan-4f26c62c8691
Best regards,
--
Enric Balletbo i Serra <eballetb@xxxxxxxxxx>
