Re: [PATCH 6/6] ide: rework handling of serialized ports

[Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>]

On Tuesday 04 November 2008, Sergei Shtylyov wrote:
> Hello, I wrote:
> 
> >> Index: b/drivers/ide/ide-probe.c
> >> ===================================================================
> >> --- a/drivers/ide/ide-probe.c
> >> +++ b/drivers/ide/ide-probe.c
> 
> > [...]
> 
> >> @@ -1436,10 +1398,8 @@ static void ide_init_port(ide_hwif_t *hw
> >>      }
> >>  
> >>      if ((d->host_flags & IDE_HFLAG_SERIALIZE) ||
> >> -        ((d->host_flags & IDE_HFLAG_SERIALIZE_DMA) && hwif->dma_base)) {
> >> -        if (hwif->mate)
> >> -            hwif->mate->serialized = hwif->serialized = 1;
> >> -    }
> >> +        ((d->host_flags & IDE_HFLAG_SERIALIZE_DMA) && hwif->dma_base))
> >> +        hwif->host_flags |= IDE_HFLAG_SERIALIZE;
> 
> >    I don't see what use is forcing this flag at all here -- it doesn't 
> > seem to be checked only in init_irq() now, so this *if* could just be 
> > moved there...
> 
>     Oops, rephrasing hurts sometimes: I meant "it seems", of course. :-)

I prefer to leave it in ide_init_port() because the future ide_hwgroup_t
removal depends on this flag in deciding whether serialization is needed.

Actually it is better to force the flag on host instead of port so:

...
v2:
* Set host's ->host_flags field instead of port's copy.
...
diff -u b/drivers/ide/hpt366.c b/drivers/ide/hpt366.c
--- b/drivers/ide/hpt366.c
+++ b/drivers/ide/hpt366.c
@@ -1303,7 +1303,7 @@
 		 * Clock is shared between the channels,
 		 * so we'll have to serialize them... :-(
 		 */
-		hwif->host_flags |= IDE_HFLAG_SERIALIZE;
+		hwif->host->host_flags |= IDE_HFLAG_SERIALIZE;
 		hwif->rw_disk = &hpt3xxn_rw_disk;
 	}
 }
diff -u b/drivers/ide/ide-probe.c b/drivers/ide/ide-probe.c
--- b/drivers/ide/ide-probe.c
+++ b/drivers/ide/ide-probe.c
@@ -1030,7 +1030,7 @@
 		ide_hwif_t *h = ide_ports[index];
 
 		if (h && h->hwgroup) {  /* scan only initialized ports */
-			if (hwif->host_flags & IDE_HFLAG_SERIALIZE) {
+			if (hwif->host->host_flags & IDE_HFLAG_SERIALIZE) {
 				if (hwif->host == h->host)
 					match = h;
 			}
@@ -1399,7 +1399,7 @@
 
 	if ((d->host_flags & IDE_HFLAG_SERIALIZE) ||
 	    ((d->host_flags & IDE_HFLAG_SERIALIZE_DMA) && hwif->dma_base))
-		hwif->host_flags |= IDE_HFLAG_SERIALIZE;
+		hwif->host->host_flags |= IDE_HFLAG_SERIALIZE;
 
 	if (d->host_flags & IDE_HFLAG_RQSIZE_256)
 		hwif->rqsize = 256;