dmaengine: qcom_hidma: add error reporting for tx_status

The HIDMA driver is capable of error detection. However, the error was
not being passed back to the client when tx_status API is called.

Changing the error handling behavior to follow this oder.

1. dmaengine asserts error interrupt
2. Driver receives and mark's the txn as error
3. Driver completes the txn and intimates the client. No further
   submissions. Drop the locks before calling callback, as subsequent
   processing by client maybe in callback thread.
4. Client invokes status and you can return error
5. On error, client calls terminate_all. You can reset channel, free all
   descriptors in the active, pending and completed lists
6. Client prepares new txn and so on.

As part of this work, got rid of the reset in the interrupt handler when
an error happens and the HW is put into disabled state. The only way to
recover is for the client to terminate the channel.

Signed-off-by: Sinan Kaya <okaya@codeaurora.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/qcom/hidma.h

@@ -72,7 +72,6 @@ struct hidma_lldev {
 
 	u32 tre_write_offset;           /* TRE write location              */
 	struct tasklet_struct task;	/* task delivering notifications   */
-	struct tasklet_struct rst_task;	/* task to reset HW                */
 	DECLARE_KFIFO_PTR(handoff_fifo,
 		struct hidma_tre *);    /* pending TREs FIFO               */
 };
@@ -89,6 +88,7 @@ struct hidma_chan {
 	bool				allocated;
 	char				dbg_name[16];
 	u32				dma_sig;
+	dma_cookie_t			last_success;
 
 	/*
 	 * active descriptor on this channel