diff options
Diffstat (limited to 'drivers/pci/pci-aardvark.c')
-rw-r--r-- | drivers/pci/pci-aardvark.c | 73 |
1 files changed, 56 insertions, 17 deletions
diff --git a/drivers/pci/pci-aardvark.c b/drivers/pci/pci-aardvark.c index 815b26162f..cf6e30f936 100644 --- a/drivers/pci/pci-aardvark.c +++ b/drivers/pci/pci-aardvark.c @@ -234,19 +234,19 @@ static int pcie_advk_addr_valid(pci_dev_t bdf, int first_busno) * * Wait up to 1.5 seconds for PIO access to be accomplished. * - * Return 1 (true) if PIO access is accomplished. - * Return 0 (false) if PIO access is timed out. + * Return positive - retry count if PIO access is accomplished. + * Return negative - error if PIO access is timed out. */ static int pcie_advk_wait_pio(struct pcie_advk *pcie) { uint start, isr; uint count; - for (count = 0; count < PIO_MAX_RETRIES; count++) { + for (count = 1; count <= PIO_MAX_RETRIES; count++) { start = advk_readl(pcie, PIO_START); isr = advk_readl(pcie, PIO_ISR); if (!start && isr) - return 1; + return count; /* * Do not check the PIO state too frequently, * 100us delay is appropriate. @@ -255,7 +255,7 @@ static int pcie_advk_wait_pio(struct pcie_advk *pcie) } dev_err(pcie->dev, "PIO read/write transfer time out\n"); - return 0; + return -ETIMEDOUT; } /** @@ -265,11 +265,13 @@ static int pcie_advk_wait_pio(struct pcie_advk *pcie) * @allow_crs: Only for read requests, if CRS response is allowed * @read_val: Pointer to the read result * + * Return: 0 on success */ static int pcie_advk_check_pio_status(struct pcie_advk *pcie, bool allow_crs, uint *read_val) { + int ret; uint reg; unsigned int status; char *strcomp_status, *str_posted; @@ -282,6 +284,7 @@ static int pcie_advk_check_pio_status(struct pcie_advk *pcie, case PIO_COMPLETION_STATUS_OK: if (reg & PIO_ERR_STATUS) { strcomp_status = "COMP_ERR"; + ret = -EFAULT; break; } /* Get the read result */ @@ -289,40 +292,46 @@ static int pcie_advk_check_pio_status(struct pcie_advk *pcie, *read_val = advk_readl(pcie, PIO_RD_DATA); /* No error */ strcomp_status = NULL; + ret = 0; break; case PIO_COMPLETION_STATUS_UR: strcomp_status = "UR"; + ret = -EOPNOTSUPP; break; case PIO_COMPLETION_STATUS_CRS: if (allow_crs && read_val) { /* For reading, CRS is not an error status. */ *read_val = CFG_RD_CRS_VAL; strcomp_status = NULL; + ret = 0; } else { strcomp_status = "CRS"; + ret = -EAGAIN; } break; case PIO_COMPLETION_STATUS_CA: strcomp_status = "CA"; + ret = -ECANCELED; break; default: strcomp_status = "Unknown"; + ret = -EINVAL; break; } if (!strcomp_status) - return 0; + return ret; if (reg & PIO_NON_POSTED_REQ) str_posted = "Non-posted"; else str_posted = "Posted"; - dev_err(pcie->dev, "%s PIO Response Status: %s, %#x @ %#x\n", + dev_dbg(pcie->dev, "%s PIO Response Status: %s, %#x @ %#x\n", str_posted, strcomp_status, reg, advk_readl(pcie, PIO_ADDR_LS)); - return -EFAULT; + return ret; } /** @@ -345,6 +354,7 @@ static int pcie_advk_read_config(const struct udevice *bus, pci_dev_t bdf, enum pci_size_t size) { struct pcie_advk *pcie = dev_get_priv(bus); + int retry_count; bool allow_crs; uint reg; int ret; @@ -358,7 +368,18 @@ static int pcie_advk_read_config(const struct udevice *bus, pci_dev_t bdf, return 0; } - allow_crs = (offset == PCI_VENDOR_ID) && (size == 4); + /* + * Returning fabricated CRS value (0xFFFF0001) by PCIe Root Complex to + * OS is allowed only for 4-byte PCI_VENDOR_ID config read request and + * only when CRSSVE bit in Root Port PCIe device is enabled. In all + * other error PCIe Root Complex must return all-ones. + * Aardvark HW does not have Root Port PCIe device and U-Boot does not + * implement emulation of this device. + * U-Boot currently does not support handling of CRS return value for + * PCI_VENDOR_ID config read request and also does not set CRSSVE bit. + * Therefore disable returning CRS response for now. + */ + allow_crs = false; if (advk_readl(pcie, PIO_START)) { dev_err(pcie->dev, @@ -368,7 +389,7 @@ static int pcie_advk_read_config(const struct udevice *bus, pci_dev_t bdf, return 0; } *valuep = pci_get_ff(size); - return -EINVAL; + return -EAGAIN; } /* Program the control register */ @@ -385,21 +406,29 @@ static int pcie_advk_read_config(const struct udevice *bus, pci_dev_t bdf, advk_writel(pcie, reg, PIO_ADDR_LS); advk_writel(pcie, 0, PIO_ADDR_MS); + retry_count = 0; + +retry: /* Start the transfer */ advk_writel(pcie, 1, PIO_ISR); advk_writel(pcie, 1, PIO_START); - if (!pcie_advk_wait_pio(pcie)) { + ret = pcie_advk_wait_pio(pcie); + if (ret < 0) { if (allow_crs) { *valuep = CFG_RD_CRS_VAL; return 0; } *valuep = pci_get_ff(size); - return -EINVAL; + return ret; } + retry_count += ret; + /* Check PIO status and get the read result */ ret = pcie_advk_check_pio_status(pcie, allow_crs, ®); + if (ret == -EAGAIN && retry_count < PIO_MAX_RETRIES) + goto retry; if (ret) { *valuep = pci_get_ff(size); return ret; @@ -461,7 +490,9 @@ static int pcie_advk_write_config(struct udevice *bus, pci_dev_t bdf, enum pci_size_t size) { struct pcie_advk *pcie = dev_get_priv(bus); + int retry_count; uint reg; + int ret; dev_dbg(pcie->dev, "PCIE CFG write: (b,d,f)=(%2d,%2d,%2d) ", PCI_BUS(bdf), PCI_DEV(bdf), PCI_FUNC(bdf)); @@ -476,7 +507,7 @@ static int pcie_advk_write_config(struct udevice *bus, pci_dev_t bdf, if (advk_readl(pcie, PIO_START)) { dev_err(pcie->dev, "Previous PIO read/write transfer is still running\n"); - return -EINVAL; + return -EAGAIN; } /* Program the control register */ @@ -504,16 +535,24 @@ static int pcie_advk_write_config(struct udevice *bus, pci_dev_t bdf, advk_writel(pcie, reg, PIO_WR_DATA_STRB); dev_dbg(pcie->dev, "\tPIO req. - strb = 0x%02x\n", reg); + retry_count = 0; + +retry: /* Start the transfer */ advk_writel(pcie, 1, PIO_ISR); advk_writel(pcie, 1, PIO_START); - if (!pcie_advk_wait_pio(pcie)) { - return -EINVAL; - } + ret = pcie_advk_wait_pio(pcie); + if (ret < 0) + return ret; + + retry_count += ret; /* Check PIO status */ - return pcie_advk_check_pio_status(pcie, false, NULL); + ret = pcie_advk_check_pio_status(pcie, false, NULL); + if (ret == -EAGAIN && retry_count < PIO_MAX_RETRIES) + goto retry; + return ret; } /** |