[BUG] scsi: wd719x: accessing the data mapped to streaming DMA

From: Jia-Ju Bai
Date: Sun Aug 02 2020 - 09:19:07 EST

In wd719x_queuecommand(), "scb" is mapped to streaming DMA:
 scb->phys = dma_map_single(..., scb, ...);

Then "scb" is accessed at many places in this function, such as:
 scb->data_length = 0;
 scb->data_p = 0;

These accesses may cause data inconsistency between CPU cache and hardware.

I am not sure how to properly fix this problem, and thus I only report it.

Best wishes,
Jia-Ju Bai