Thanks for the review and comments. I will incorporate the comments
from you and Jingoo Han in next version.
-Tanmay
On Fri, Mar 14, 2014 at 5:18 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> On Thursday 06 March 2014, Tanmay Inamdar wrote:
>
>> +static inline void xgene_pcie_cfg_out16(void __iomem *addr, u16 val)
>> +{
>> + u64 temp_addr = (u64)addr & ~0x3;
>
> Please use 'unsigned long' as the type for calculations like this one,
> to make the code more portable. You mentioned before that the same PCI
> host controller is used on some ppc4xx, and we may want to share the
> code later.
>
>> +static int xgene_pcie_read_config(struct pci_bus *bus, unsigned int devfn,
>> + int offset, int len, u32 *val)
>> +{
>> + struct xgene_pcie_port *port = bus->sysdata;
>> + void __iomem *addr;
>> + u8 val8;
>> + u16 val16;
>> +
>> + if ((pci_is_root_bus(bus) && devfn != 0) || !port->link_up)
>> + return PCIBIOS_DEVICE_NOT_FOUND;
>> +
>> + xgene_pcie_set_rtdid_reg(bus, devfn);
>> + addr = xgene_pcie_get_cfg_base(bus);
>> + switch (len) {
>> + case 1:
>> + xgene_pcie_cfg_in8(addr + offset, &val8);
>> + *val = val8;
>> + break;
>
> Actually it would be better to just pass both addr and offset
> down into the low-level accessors and then do the calculation
> on 'offset', which is already a scalar.
>
>> +static void xgene_pcie_poll_linkup(struct xgene_pcie_port *port,
>> + u32 *lanes, u32 *speed)
>> +{
>> + void __iomem *csr_base = port->csr_base;
>> + u32 val32;
>> + u64 start_time, time;
>> +
>> + /*
>> + * A component enters the LTSSM Detect state within
>> + * 20ms of the end of fundamental core reset.
>> + */
>> + msleep(XGENE_LTSSM_DETECT_WAIT);
>> + port->link_up = 0;
>> + start_time = jiffies;
>> + do {
>> + val32 = readl(csr_base + PCIECORE_CTLANDSTATUS);
>> + if (val32 & LINK_UP_MASK) {
>> + port->link_up = 1;
>> + *speed = PIPE_PHY_RATE_RD(val32);
>> + val32 = readl(csr_base + BRIDGE_STATUS_0);
>> + *lanes = val32 >> 26;
>> + break;
>> + }
>> + msleep(1);
>> + time = jiffies_to_msecs(jiffies - start_time);
>> + } while (time <= XGENE_LTSSM_L0_WAIT);
>> +}
>
> This can be written ina simpler way using 'time_before()'.
>
>> +/* Return 0 on success */
>> +static int xgene_pcie_init_ecc(struct xgene_pcie_port *port)
>> +{
>> + void __iomem *csr_base = port->csr_base;
>> + u64 start_time, time = 0;
>> + u32 val;
>> +
>> + val = readl(csr_base + MEM_RAM_SHUTDOWN);
>> + if (!val)
>> + return 0;
>> + writel(0x0, csr_base + MEM_RAM_SHUTDOWN);
>> + start_time = jiffies;
>> + do {
>> + val = readl(csr_base + BLOCK_MEM_RDY);
>> + if (val == BLOCK_MEM_RDY_VAL)
>> + break;
>> + msleep(1);
>> + time = jiffies_to_msecs(jiffies - start_time);
>> + } while (time < XGENE_PCIE_ECC_TIMEOUT);
>
> Same here.
>
>> +static int xgene_pcie_init_port(struct xgene_pcie_port *port)
>> +{
>> + int rc;
>> +
>> + port->clk = clk_get(port->dev, NULL);
>> + if (IS_ERR_OR_NULL(port->clk)) {
>> + dev_err(port->dev, "clock not available\n");
>> + return -ENODEV;
>> + }
>
> Practically every use of IS_ERR_OR_NULL() is a bug, don't do that.
> NULL is a valid return code from clk_get(), and should not be
> treated as an error.
>
>
>> +static int xgene_pcie_map_ranges(struct xgene_pcie_port *port,
>> + struct pci_host_bridge *bridge,
>> + u64 cfg_addr)
>> +{
>> + struct device *dev = port->dev;
>> + struct pci_host_bridge_window *window;
>> +
>> + list_for_each_entry(window, &bridge->windows, list) {
>> + struct resource *res = window->res;
>> + u64 restype = resource_type(res);
>> + dev_dbg(port->dev, "0x%08lx 0x%016llx...0x%016llx\n",
>> + res->flags, res->start, res->end);
>> +
>> + switch (restype) {
>> + case IORESOURCE_IO:
>> + xgene_pcie_setup_ob_reg(port, res, OMR2BARL,
>> + bridge->io_base);
>> + BUG_ON(pci_ioremap_io(res, bridge->io_base) < 0);
>> + break;
>
> No need to BUG_ON() here, this is not a fatal condition, just
> don't register the I/O space resource if this fails.
>
> I think as the PCI base support patch series evolves, you will actually
> not have to do this at all.
>
> Arnd
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