vt6420 completely loses its ability to raise IRQ for ATAPI devices if
ATA_NIEN is diddled with in ->freeze. Further investigation is
necessary to determine whether this problem is shared on other
controllers but it doesn't seem to be at this point.
Make vt6420's ->freeze only clear IRQ to fix this problem. This makes
vt6420 relatively more prone to IRQ storms but the controller is way
too braindamaged to worry about that anyway.
Signed-off-by: Tejun Heo <htejun@xxxxxxxxx>
---
Jeff, this fix is verified to fix J. Taimr's case and a few other
reported that 2.6.20-rc5 fixed their ATAPI detection problems too. We
still have several case to hunt down but getting verified fixes in
early helps separating different causes. Please include this in
#upstream-fixes. Thanks.
drivers/ata/sata_via.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
Index: work/drivers/ata/sata_via.c
===================================================================
--- work.orig/drivers/ata/sata_via.c
+++ work/drivers/ata/sata_via.c
@@ -74,6 +74,7 @@ enum {
static int svia_init_one (struct pci_dev *pdev, const struct pci_device_id *ent);
static u32 svia_scr_read (struct ata_port *ap, unsigned int sc_reg);
static void svia_scr_write (struct ata_port *ap, unsigned int sc_reg, u32 val);
+static void svia_noop_freeze(struct ata_port *ap);
static void vt6420_error_handler(struct ata_port *ap);
static const struct pci_device_id svia_pci_tbl[] = {
@@ -128,7 +129,7 @@ static const struct ata_port_operations
.qc_issue = ata_qc_issue_prot,
.data_xfer = ata_pio_data_xfer,
- .freeze = ata_bmdma_freeze,
+ .freeze = svia_noop_freeze,
.thaw = ata_bmdma_thaw,
.error_handler = vt6420_error_handler,
.post_internal_cmd = ata_bmdma_post_internal_cmd,
@@ -204,6 +205,15 @@ static void svia_scr_write (struct ata_p
outl(val, ap->ioaddr.scr_addr + (4 * sc_reg));
}
+static void svia_noop_freeze(struct ata_port *ap)
+{
+ /* Some VIA controllers choke if ATA_NIEN is manipulated in
+ * certain way. Leave it alone and just clear pending IRQ.
+ */
+ ata_chk_status(ap);
+ ap->ops->irq_clear(ap);
+}
+
/**
* vt6420_prereset - prereset for vt6420
* @ap: target ATA port
-
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