Tejun / Alan,
I'm now venturing into the labyrinth that is presented
when one tries to combine a nice FIS-based controller/driver
with old school BMDMA for ATAPI only.
To preserve my own sanity, I'm opting for basic PIO-only
support for ATAPI to begin with. Then I'll add the DMA functions
to speed things up afterward.
This patch (below) seems to work 100% okay for me here,
apart from the sata_mv chipset errata warnings it generates
(another thing I hope to tidy up soon-ish).
Question: is this the "right" way to force PIO-only,
or is there a better mechanism that I'm missing.
It just seems.. too easy this way. :)
Thanks.
* * *
Add basic ATAPI support to sata_mv using PIO + polling.
DMA support will be added later.
Signed-off-by: Mark Lord <mlord@xxxxxxxxx>
--- old/drivers/ata/sata_mv.c 2009-01-23 11:20:57.000000000 -0500
+++ linux/drivers/ata/sata_mv.c 2009-01-23 12:02:20.000000000 -0500
@@ -120,7 +120,7 @@
MV_FLAG_IRQ_COALESCE = (1 << 29), /* IRQ coalescing capability */
MV_COMMON_FLAGS = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
- ATA_FLAG_MMIO | ATA_FLAG_NO_ATAPI |
+ ATA_FLAG_MMIO |
ATA_FLAG_PIO_POLLING,
MV_6XXX_FLAGS = MV_FLAG_IRQ_COALESCE,
@@ -502,6 +502,7 @@
static void mv_eh_freeze(struct ata_port *ap);
static void mv_eh_thaw(struct ata_port *ap);
static void mv6_dev_config(struct ata_device *dev);
+static void mv_dev_config(struct ata_device *dev);
static void mv5_phy_errata(struct mv_host_priv *hpriv, void __iomem *mmio,
unsigned int port);
@@ -576,6 +577,7 @@
.error_handler = ata_std_error_handler, /* avoid SFF EH */
.post_internal_cmd = ATA_OP_NULL,
+ .dev_config = mv_dev_config,
.scr_read = mv5_scr_read,
.scr_write = mv5_scr_write,
@@ -597,7 +599,7 @@
static struct ata_port_operations mv_iie_ops = {
.inherits = &mv6_ops,
- .dev_config = ATA_OP_NULL,
+ .dev_config = mv_dev_config,
.qc_prep = mv_qc_prep_iie,
};
@@ -1082,6 +1084,21 @@
return -EINVAL;
}
+static void mv_dev_config(struct ata_device *adev)
+{
+ /*
+ * Support ATAPI devices via PIO-only for now.
+ * DMA support is planned for later.
+ */
+ if (adev->class == ATA_DEV_ATAPI) {
+ adev->xfer_shift = ATA_SHIFT_PIO;
+ adev->flags |= ATA_DFLAG_PIO;
+ ata_dev_printk(adev, KERN_INFO, DRV_NAME
+ ": ATAPI DMA not yet implemented;"
+ " using (slow) PIO for now\n");
+ }
+}
+
static void mv6_dev_config(struct ata_device *adev)
{
/*
@@ -1097,6 +1114,7 @@
"NCQ disabled for command-based switching\n");
}
}
+ mv_dev_config(adev);
}
static int mv_qc_defer(struct ata_queued_cmd *qc)
--
To unsubscribe from this list: send the line "unsubscribe linux-ide" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
