From mboxrd@z Thu Jan 1 00:00:00 1970
From: Pat LaVarre
Subject: [PATCH] libata SATAPI no data
Date: 26 May 2004 15:41:55 -0600
Sender: linux-ide-owner@vger.kernel.org
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Wed, 26 May 2004 17:41:58 -0400
List-Id: linux-ide@vger.kernel.org
To: Jeff Garzik
Cc: linux-ide@vger.kernel.org
Jeff G:
> Subject: Re: [PATCH] atapi request sense work
> ...
> I'll try naming the fragment of code that
> fetches the host_stat so I can concisely say
> do that only when appropriate.
As discussed previously, we need a patch to make SATAPI work when the
device agrees to actually copy no data without error, quite apart from
us making auto sense work in the "[PATCH] atapi request sense work"
thread.
Do you like this conceptually trivial patch? I name this
satapi.hn.patch. I think its essence is:
@@ -2650,11 +2658,14 @@ inline unsigned int ata_host_intr (struc
case ATA_PROT_NODATA:
status = ata_busy_wait(ap, ATA_BUSY | ATA_DRQ, 1000);
DPRINTK("BUS_NODATA (drv_stat 0x%X)\n", status);
- ata_qc_complete(qc, status);
+ host_stat = ata_check_bmdma(ap);
+ DPRINTK("BUS_NODATA (host_stat 0x%X)\n", host_stat);
+ ata_dma_complete(qc, host_stat);
Here I chose { inline } over { static inline } because lately I saw you
counting libata.ko bytes.
Here I chose u8 over int because lxr.linux.no/source/ suggests Linux
readb and inb return u8.
Here I chose DPRINTK over VPRINTK to match the choices nearby.
Here I haven't yet seen the { DPRINTK("irq trappable\n"); } trigger
fire.
I'm not especially surprised to discover that PCI IDE BMDMA seemingly
passes back a PCI interrupt whenever it catches an IDE interrupt, no
matter if DMA was recently in progress or not, but I also haven't found
a datasheet to tell me explicitly to expect that behaviour.
Pat LaVarre
P.S.
diff -b within the patch assures me I did delete two occurrences of five
source lines and substitute two calls and a third new call to those same
five lines.
(To my newbie surprise, I find I cannot easily compare binary to prove
some of my change has no substantive effect. Instead I find inserting
blank lines changes the libata.ko binary, even if I think to turn off
ATA_VERBOSE_DEBUG and ATA_DEBUG.)
diff -Nurp linux-2.6.7-rc1-bk3/drivers/scsi/libata-core.c linux-2.6.7-rc1-bk3-pel/drivers/scsi/libata-core.c
--- linux-2.6.7-rc1-bk3/drivers/scsi/libata-core.c 2004-05-25 14:47:00.000000000 -0600
+++ linux-2.6.7-rc1-bk3-pel/drivers/scsi/libata-core.c 2004-05-26 15:35:31.512139768 -0600
@@ -2146,6 +2146,22 @@ static void ata_pio_task(void *_data)
}
/**
+ * ata_check_bmdma - read PCI IDE BMDMA status
+ * @ap: struct ata_port
+ */
+
+static u8 ata_check_bmdma(struct ata_port *ap)
+{
+ u8 host_stat;
+ if (ap->flags & ATA_FLAG_MMIO) {
+ void *mmio = (void *) ap->ioaddr.bmdma_addr;
+ host_stat = readb(mmio + ATA_DMA_STATUS);
+ } else
+ host_stat = inb(ap->ioaddr.bmdma_addr + ATA_DMA_STATUS);
+ return host_stat;
+}
+
+/**
* ata_eng_timeout - Handle timeout of queued command
* @ap: Port on which timed-out command is active
*
@@ -2188,11 +2204,7 @@ void ata_eng_timeout(struct ata_port *ap
switch (qc->tf.protocol) {
case ATA_PROT_DMA:
- if (ap->flags & ATA_FLAG_MMIO) {
- void *mmio = (void *) ap->ioaddr.bmdma_addr;
- host_stat = readb(mmio + ATA_DMA_STATUS);
- } else
- host_stat = inb(ap->ioaddr.bmdma_addr + ATA_DMA_STATUS);
+ host_stat = ata_check_bmdma(ap);
printk(KERN_ERR "ata%u: DMA timeout, stat 0x%x\n",
ap->id, host_stat);
@@ -2622,11 +2634,7 @@ inline unsigned int ata_host_intr (struc
/* BMDMA completion */
case ATA_PROT_DMA:
case ATA_PROT_ATAPI_DMA:
- if (ap->flags & ATA_FLAG_MMIO) {
- void *mmio = (void *) ap->ioaddr.bmdma_addr;
- host_stat = readb(mmio + ATA_DMA_STATUS);
- } else
- host_stat = inb(ap->ioaddr.bmdma_addr + ATA_DMA_STATUS);
+ host_stat = ata_check_bmdma(ap);
VPRINTK("BUS_DMA (host_stat 0x%X)\n", host_stat);
if (!(host_stat & ATA_DMA_INTR)) {
@@ -2650,11 +2658,14 @@ inline unsigned int ata_host_intr (struc
case ATA_PROT_NODATA:
status = ata_busy_wait(ap, ATA_BUSY | ATA_DRQ, 1000);
DPRINTK("BUS_NODATA (drv_stat 0x%X)\n", status);
- ata_qc_complete(qc, status);
+ host_stat = ata_check_bmdma(ap);
+ DPRINTK("BUS_NODATA (host_stat 0x%X)\n", host_stat);
+ ata_dma_complete(qc, host_stat);
handled = 1;
break;
default:
+ DPRINTK("irq trappable\n");
ap->stats.idle_irq++;
#ifdef ATA_IRQ_TRAP
diff -Nurp linux-2.6.7-rc1-bk3/drivers/scsi/libata-scsi.c linux-2.6.7-rc1-bk3-pel/drivers/scsi/libata-scsi.c