This patch fixes an old bug: accesses to device registers from the
interrupt handler (after reselection, DMA completion etc.) could mess
up a device register access elsewhere, if the latter takes place outside
of an irq lock (during selection etc.).
Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/atari_scsi.c | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/atari_scsi.c b/drivers/scsi/atari_scsi.c
index a59ad94..862f30c 100644
--- a/drivers/scsi/atari_scsi.c
+++ b/drivers/scsi/atari_scsi.c
@@ -670,14 +670,26 @@ static void atari_scsi_tt_reg_write(unsigned char reg, unsigned char value)
static unsigned char atari_scsi_falcon_reg_read(unsigned char reg)
{
- dma_wd.dma_mode_status= (u_short)(0x88 + reg);
- return (u_char)dma_wd.fdc_acces_seccount;
+ unsigned long flags;
+ unsigned char result;
+
+ reg += 0x88;
+ local_irq_save(flags);
+ dma_wd.dma_mode_status = (u_short)reg;
+ result = (u_char)dma_wd.fdc_acces_seccount;
+ local_irq_restore(flags);
+ return result;
}
static void atari_scsi_falcon_reg_write(unsigned char reg, unsigned char value)
{
- dma_wd.dma_mode_status = (u_short)(0x88 + reg);
+ unsigned long flags;
+
+ reg += 0x88;
+ local_irq_save(flags);
+ dma_wd.dma_mode_status = (u_short)reg;
dma_wd.fdc_acces_seccount = (u_short)value;
+ local_irq_restore(flags);
}
--
2.7.3
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