From: Finn Thain <fthain@telegraphics.com.au>
Date: Sun, 15 Jan 2017 23:50:57 +0000 (-0500)
Subject: scsi: atari_scsi: Reset DMA during bus reset only under ST-DMA lock
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=546a4d1812b647fddad58a4416c7a44c27bb0499;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

scsi: atari_scsi: Reset DMA during bus reset only under ST-DMA lock

The atari_scsi driver should not access Falcon DMA chip registers unless
it has acquired exclusive access to that chip. If the driver doesn't
have exclusive access then there's no need for a DMA reset as there are
no scsi commands in progress.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
---

diff --git a/drivers/scsi/atari_scsi.c b/drivers/scsi/atari_scsi.c
index b2ffab6577a6..f792420c533e 100644
--- a/drivers/scsi/atari_scsi.c
+++ b/drivers/scsi/atari_scsi.c
@@ -682,7 +682,8 @@ static int atari_scsi_bus_reset(struct scsi_cmnd *cmd)
 	if (IS_A_TT()) {
 		tt_scsi_dma.dma_ctrl = 0;
 	} else {
-		st_dma.dma_mode_status = 0x90;
+		if (stdma_is_locked_by(scsi_falcon_intr))
+			st_dma.dma_mode_status = 0x90;
 		atari_dma_active = 0;
 		atari_dma_orig_addr = NULL;
 	}