1 Make ahci_start_engine() and ahci_stop_engine more consistent with AHCI
spec 1.1
2 Change their input parameter from ap to port_mmio
Signed-off-by: Forrest Zhao <forrest.zhao@xxxxxxxxx>
---
drivers/scsi/ahci.c | 51 +++++++++++++++++++++++++++++++++++++++++++++------
1 files changed, 45 insertions(+), 6 deletions(-)
9ba56ff63c5f01f0a7280f15189c952f2fd7f2a1
diff --git a/drivers/scsi/ahci.c b/drivers/scsi/ahci.c
index 45fd71d..d2b35c4 100644
--- a/drivers/scsi/ahci.c
+++ b/drivers/scsi/ahci.c
@@ -200,6 +200,8 @@ static void ahci_scr_write (struct ata_p
static int ahci_init_one (struct pci_dev *pdev, const struct pci_device_id *ent);
static unsigned int ahci_qc_issue(struct ata_queued_cmd *qc);
static irqreturn_t ahci_interrupt (int irq, void *dev_instance, struct pt_regs *regs);
+static int ahci_start_engine(void __iomem *port_mmio);
+static int ahci_stop_engine(void __iomem *port_mmio);
static int ahci_probe_reset(struct ata_port *ap, unsigned int *classes);
static void ahci_irq_clear(struct ata_port *ap);
static int ahci_port_start(struct ata_port *ap);
@@ -482,14 +484,18 @@ static void ahci_scr_write (struct ata_p
writel(val, (void __iomem *) ap->ioaddr.scr_addr + (sc_reg * 4));
}
-static int ahci_stop_engine(struct ata_port *ap)
+static int ahci_stop_engine(void __iomem *port_mmio)
{
- void __iomem *mmio = ap->host_set->mmio_base;
- void __iomem *port_mmio = ahci_port_base(mmio, ap->port_no);
int work;
u32 tmp;
tmp = readl(port_mmio + PORT_CMD);
+
+ /* Check if the HBA is idle */
+ if ((tmp & (PORT_CMD_START | PORT_CMD_LIST_ON)) == 0)
+ return 0;
+
+ /* Setting HBA to idle */
tmp &= ~PORT_CMD_START;
writel(tmp, port_mmio + PORT_CMD);
@@ -507,16 +513,49 @@ static int ahci_stop_engine(struct ata_p
return -EIO;
}
-static void ahci_start_engine(struct ata_port *ap)
+static int ahci_start_engine(void __iomem *port_mmio)
{
- void __iomem *mmio = ap->host_set->mmio_base;
- void __iomem *port_mmio = ahci_port_base(mmio, ap->port_no);
u32 tmp;
+ int work = 1000;
+ /*
+ * Get current status
+ */
tmp = readl(port_mmio + PORT_CMD);
+
+ /*
+ * AHCI rev 1.1 section 10.3.1:
+ * Software shall not set PxCMD.ST to '1' until it verifies
+ * that PxCMD.CR is '0' and has set PxCMD.FRE to '1'
+ */
+ if ((tmp & PORT_CMD_FIS_RX) == 0)
+ return -EPERM;
+
+ /*
+ * wait for engine to become idle.
+ */
+ while (work-- > 0) {
+ tmp = readl(port_mmio + PORT_CMD);
+ if ((tmp & PORT_CMD_LIST_ON) == 0)
+ break;
+ udelay(10);
+ }
+
+ if (!work) {
+ /*
+ * We need to do a port reset / HBA reset here
+ */
+ return -EBUSY;
+ }
+
+ /*
+ * Start DMA
+ */
tmp |= PORT_CMD_START;
writel(tmp, port_mmio + PORT_CMD);
readl(port_mmio + PORT_CMD); /* flush */
+
+ return 0;
}
static unsigned int ahci_dev_classify(struct ata_port *ap)
--
1.2.6
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