@@ -58,6 +58,7 @@
#define PIO_COMPLETION_STATUS_CRS 2
#define PIO_COMPLETION_STATUS_CA 4
#define PIO_NON_POSTED_REQ BIT(10)
+#define PIO_ERR_STATUS BIT(11)
#define PIO_ADDR_LS (PIO_BASE_ADDR + 0x8)
#define PIO_ADDR_MS (PIO_BASE_ADDR + 0xc)
#define PIO_WR_DATA (PIO_BASE_ADDR + 0x10)
@@ -461,7 +462,7 @@ static void advk_pcie_setup_hw(struct advk_pcie *pcie)
advk_writel(pcie, reg, PCIE_CORE_CMD_STATUS_REG);
}
-static void advk_pcie_check_pio_status(struct advk_pcie *pcie)
+static int advk_pcie_check_pio_status(struct advk_pcie *pcie, u32 *val)
{
struct device *dev = &pcie->pdev->dev;
u32 reg;
@@ -472,14 +473,49 @@ static void advk_pcie_check_pio_status(struct advk_pcie *pcie)
status = (reg & PIO_COMPLETION_STATUS_MASK) >>
PIO_COMPLETION_STATUS_SHIFT;
- if (!status)
- return;
-
+ /*
+ * According to HW spec, the PIO status check sequence as below:
+ * 1) even if COMPLETION_STATUS(bit9:7) indicates successful,
+ * it still needs to check Error Status(bit11), only when this bit
+ * indicates no error happen, the operation is successful.
+ * 2) value Unsupported Request(1) of COMPLETION_STATUS(bit9:7) only
+ * means a PIO write error, and for PIO read it is successful with
+ * a read value of 0xFFFFFFFF.
+ * 3) value Completion Retry Status(CRS) of COMPLETION_STATUS(bit9:7)
+ * only means a PIO write error, and for PIO read it is successful
+ * with a read value of 0xFFFF0001.
+ * 4) value Completer Abort (CA) of COMPLETION_STATUS(bit9:7) means
+ * error for both PIO read and PIO write operation.
+ * 5) other errors are indicated as 'unknown'.
+ */
switch (status) {
+ case PIO_COMPLETION_STATUS_OK:
+ if (reg & PIO_ERR_STATUS) {
+ strcomp_status = "COMP_ERR";
+ break;
+ }
+ /* Get the read result */
+ if (val)
+ *val = advk_readl(pcie, PIO_RD_DATA);
+ /* No error */
+ strcomp_status = NULL;
+ break;
case PIO_COMPLETION_STATUS_UR:
strcomp_status = "UR";
break;
case PIO_COMPLETION_STATUS_CRS:
+ /* PCIe r4.0, sec 2.3.2, says:
+ * If CRS Software Visibility is not enabled, the Root Complex
+ * must re-issue the Configuration Request as a new Request.
+ * A Root Complex implementation may choose to limit the number
+ * of Configuration Request/CRS Completion Status loops before
+ * determining that something is wrong with the target of the
+ * Request and taking appropriate action, e.g., complete the
+ * Request to the host as a failed transaction.
+ *
+ * To simplify implementation do not re-issue the Configuration
+ * Request and complete the Request as a failed transaction.
+ */
strcomp_status = "CRS";
break;
case PIO_COMPLETION_STATUS_CA:
@@ -490,6 +526,9 @@ static void advk_pcie_check_pio_status(struct advk_pcie *pcie)
break;
}
+ if (!strcomp_status)
+ return 0;
+
if (reg & PIO_NON_POSTED_REQ)
str_posted = "Non-posted";
else
@@ -497,6 +536,8 @@ static void advk_pcie_check_pio_status(struct advk_pcie *pcie)
dev_err(dev, "%s PIO Response Status: %s, %#x @ %#x\n",
str_posted, strcomp_status, reg, advk_readl(pcie, PIO_ADDR_LS));
+
+ return -EFAULT;
}
static int advk_pcie_wait_pio(struct advk_pcie *pcie)
@@ -734,10 +775,13 @@ static int advk_pcie_rd_conf(struct pci_bus *bus, u32 devfn,
return PCIBIOS_SET_FAILED;
}
- advk_pcie_check_pio_status(pcie);
+ /* Check PIO status and get the read result */
+ ret = advk_pcie_check_pio_status(pcie, val);
+ if (ret < 0) {
+ *val = 0xffffffff;
+ return PCIBIOS_SET_FAILED;
+ }
- /* Get the read result */
- *val = advk_readl(pcie, PIO_RD_DATA);
if (size == 1)
*val = (*val >> (8 * (where & 3))) & 0xff;
else if (size == 2)
@@ -801,7 +845,9 @@ static int advk_pcie_wr_conf(struct pci_bus *bus, u32 devfn,
if (ret < 0)
return PCIBIOS_SET_FAILED;
- advk_pcie_check_pio_status(pcie);
+ ret = advk_pcie_check_pio_status(pcie, NULL);
+ if (ret < 0)
+ return PCIBIOS_SET_FAILED;
return PCIBIOS_SUCCESSFUL;
}