Re: More information on ATI IXP failure in git9

[Tejun Heo <htejun@gmail.com>]

[-- Attachment #1: Type: text/plain, Size: 806 bytes --]

Hello, Andi.

Andi Kleen wrote:
> Still doesn't work with it - see http://one.firstfloor.org/~andi/sata3.jpg

* SATA_IRQ bit is stuck (on all other sil controllers, this gets cleared 
when SError is cleared)

* whenever interrupt occurs (from itself or from any other ones sharing 
the IRQ), irq handler sees SATA_IRQ bit set and thus thinks it just 
received phy status changed IRQ.

* phy status change aborts the active command, so no command gets completed.

I'm attaching two patches.  The first one tries to clear SATA_IRQ by 
writing 1 to it in thaw() assuming the bit is implemented as W1C (which 
BTW is out of spec).  The second one kills SATA_IRQ handling completely. 
  I wish the first one works but if not I'll update the second one such 
that it applies only to ATI IXP.

Thanks.

-- 
tejun

[-- Attachment #2: patch0 --]
[-- Type: text/plain, Size: 490 bytes --]

diff --git a/drivers/scsi/sata_sil.c b/drivers/scsi/sata_sil.c
index bc9f918..fca5333 100644
--- a/drivers/scsi/sata_sil.c
+++ b/drivers/scsi/sata_sil.c
@@ -474,6 +474,9 @@ static void sil_thaw(struct ata_port *ap
 	ata_chk_status(ap);
 	ata_bmdma_irq_clear(ap);
 
+	/* SATA_IRQ has to be cleared manually on some controllers */
+	writel(SIL_DMA_SATA_IRQ, mmio_base + sil_port[ap->port_no].bmdma2);
+
 	/* turn on SATA IRQ */
 	writel(SIL_SIEN_N, mmio_base + sil_port[ap->port_no].sien);
 

[-- Attachment #3: patch1 --]
[-- Type: text/plain, Size: 1098 bytes --]

diff --git a/drivers/scsi/sata_sil.c b/drivers/scsi/sata_sil.c
index bc9f918..024ce28 100644
--- a/drivers/scsi/sata_sil.c
+++ b/drivers/scsi/sata_sil.c
@@ -343,6 +343,7 @@ static void sil_host_intr(struct ata_por
 	struct ata_queued_cmd *qc = ata_qc_from_tag(ap, ap->active_tag);
 	u8 status;
 
+#if 0
 	if (unlikely(bmdma2 & SIL_DMA_SATA_IRQ)) {
 		u32 serror;
 
@@ -365,6 +366,7 @@ static void sil_host_intr(struct ata_por
 
 		goto freeze;
 	}
+#endif
 
 	if (unlikely(!qc || qc->tf.ctl & ATA_NIEN))
 		goto freeze;
@@ -438,7 +440,7 @@ static irqreturn_t sil_interrupt(int irq
 			continue;
 
 		if (bmdma2 == 0xffffffff ||
-		    !(bmdma2 & (SIL_DMA_COMPLETE | SIL_DMA_SATA_IRQ)))
+		    !(bmdma2 & (SIL_DMA_COMPLETE/* | SIL_DMA_SATA_IRQ*/)))
 			continue;
 
 		sil_host_intr(ap, bmdma2);
@@ -475,7 +477,7 @@ static void sil_thaw(struct ata_port *ap
 	ata_bmdma_irq_clear(ap);
 
 	/* turn on SATA IRQ */
-	writel(SIL_SIEN_N, mmio_base + sil_port[ap->port_no].sien);
+	/*writel(SIL_SIEN_N, mmio_base + sil_port[ap->port_no].sien);*/
 
 	/* turn on IRQ */
 	tmp = readl(mmio_base + SIL_SYSCFG);