Hello.
Denis Turischev wrote:
pata_sch: fix PSTS register reading.
According to Poulsbo SCH datasheet (p. 353): "Reading reserved bits
returns
an indeterminate, inconsistent value".
Bit 7 of PSTS register read as 1 when there is slave disk drive attached,
despite being described as reserved with zero value. This causes wrong
feature
decoding in ata_sff_tf_read.
ata_sff_tf_read() doesn't decode anything.
Fix it by implementing pata_sch specific sff_tf_read with appropriate bit
masks on PSTS register.
Your patch doesn't make any sense to me -- sorry...
Signed-off-by: Denis Turischev <denis@xxxxxxxxxxxxxx>
CC: stable@xxxxxxxxxx
--- linux-2.6.33-rc4.orig/drivers/ata/pata_sch.c 2010-01-13
07:15:00.000000000 +0200
+++ linux-2.6.33-rc4/drivers/ata/pata_sch.c 2010-01-20
11:19:16.000000000 +0200
@@ -49,6 +49,11 @@
USD = (1 << 31), /* Use Synchronous DMA */
};
+/* see SCH datasheet page 353 */
+enum {
+ PSTSM = 0x7f, /* PSTS Bit Mask */
+};
+
static int sch_init_one(struct pci_dev *pdev,
const struct pci_device_id *ent);
static void sch_set_piomode(struct ata_port *ap, struct ata_device
*adev);
@@ -75,11 +80,47 @@
ATA_BMDMA_SHT(DRV_NAME),
};
+/**
+ * sch_tf_read - input device's ATA taskfile shadow registers
+ * @ap: Port from which input is read
+ * @tf: ATA taskfile register set for storing input
+ *
+ * Note: Original code is ata_sff_tf_read().
+ */
+
+static void sch_tf_read(struct ata_port *ap, struct ata_taskfile *tf)
+{
+ struct ata_ioports *ioaddr = &ap->ioaddr;
+
+ tf->command = ata_sff_check_status(ap);
+ tf->feature = ioread8(ioaddr->error_addr) && PSTSM;
1) you want a bitwise AND here (&);
2) what you're doing is wrong, you can't mask the features register
like that -- are you sure that *this* is the PSTS register?
+ tf->nsect = ioread8(ioaddr->nsect_addr);
+ tf->lbal = ioread8(ioaddr->lbal_addr);
+ tf->lbam = ioread8(ioaddr->lbam_addr);
+ tf->lbah = ioread8(ioaddr->lbah_addr);
+ tf->device = ioread8(ioaddr->device_addr);
+
+ if (tf->flags & ATA_TFLAG_LBA48) {
+ if (likely(ioaddr->ctl_addr)) {
Useless check I think -- ioaddr->ctl_addr should always be non-zero
with pata_sch.
+ iowrite8(tf->ctl | ATA_HOB, ioaddr->ctl_addr);
+ tf->hob_feature = ioread8(ioaddr->error_addr) && PSTSM;
Same comments here.
+ tf->hob_nsect = ioread8(ioaddr->nsect_addr);
+ tf->hob_lbal = ioread8(ioaddr->lbal_addr);
+ tf->hob_lbam = ioread8(ioaddr->lbam_addr);
+ tf->hob_lbah = ioread8(ioaddr->lbah_addr);
+ iowrite8(tf->ctl, ioaddr->ctl_addr);
+ ap->last_ctl = tf->ctl;
+ } else
+ WARN_ON_ONCE(1);
+ }
+}
+
static struct ata_port_operations sch_pata_ops = {
.inherits = &ata_bmdma_port_ops,
.cable_detect = ata_cable_unknown,
.set_piomode = sch_set_piomode,
.set_dmamode = sch_set_dmamode,
+ .sff_tf_read = sch_tf_read,
};
MBR, Sergei
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