dmaengine: dw-edma: eDMA: Add sync read before starting the DMA transfer in remote...

dmaengine: dw-edma: eDMA: Add sync read before starting the DMA transfer in remote setup

The Linked list element and pointer are not stored in the same memory as
the eDMA controller register. If the doorbell register is toggled before
the full write of the linked list a race condition error will occur.
In remote setup we can only use a readl to the memory to assure the full
write has occurred.

Fixes: 7e4b8a4fbe2c ("dmaengine: Add Synopsys eDMA IP version 0 support")
Reviewed-by: Serge Semin <fancer.lancer@gmail.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://lore.kernel.org/r/20240129-b4-feature_hdma_mainline-v7-6-8e8c1acb7a46@bootlin.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>