Subject: Re: linux-next: Tree for Nov 27 (scsi/aha1542)

From: James Bottomley <[email-masked]>
Date: Tue, 27 Nov 2018 21:41:24 -0800

On Wed, 2018-11-28 at 15:38 +1100, Stephen Rothwell wrote:
> Hi all,
> 
> On Tue, 27 Nov 2018 20:14:58 -0800 Randy Dunlap <[email-masked]
> g> wrote:
> > 
> > On 11/26/18 8:25 PM, Stephen Rothwell wrote:
> > > Hi all,
> > > 
> > > Changes since 20181126:
> > >   
> > 
> > on i386:
> > 
> > ERROR: "__udivdi3" [drivers/scsi/aha1542.ko] undefined!
> > 
> > somewhere in aha1542_interrupt() according to objdump.
> 
> Presumably caused by commit
> 
>   1794ef2b150d ("scsi: aha1542: convert to DMA mapping API")

Yes, it's because dma_addr_t can be u64 on pae systems but
isa_virt_to_bus only ever returns unsigned long (because an ISA
physical address can only be 24 bits).

I think this is the fix; there doesn't seem to be much point converting
to do_div given all the limitations.

James

---

diff --git a/drivers/scsi/aha1542.c b/drivers/scsi/aha1542.c
index a9c29757172f..afb693d7b44f 100644
--- a/drivers/scsi/aha1542.c
+++ b/drivers/scsi/aha1542.c
@@ -325,7 +325,7 @@ static irqreturn_t aha1542_interrupt(int irq, void *dev_id)
 			return IRQ_HANDLED;
 		};
 
-		mbo = (scsi2int(mb[mbi].ccbptr) - aha1542->ccb_handle) / sizeof(struct ccb);
+		mbo = (scsi2int(mb[mbi].ccbptr) - (unsigned long)aha1542->ccb_handle) / sizeof(struct ccb);
 		mbistatus = mb[mbi].status;
 		mb[mbi].status = 0;
 		aha1542->aha1542_last_mbi_used = mbi;