Currently the driver gets ns16550 base address in the driver probe() routine, which may potentially break any ns16550 wrapper driver that does additional initialization before calling ns16550_serial_probe().
Things are complicated that we need consider ns16550 devices on both simple-bus and PCI bus. To fix the issue we move the base address assignment for simple-bus ns16550 device back to the ofdata_to_platdata(), and assign base address for PCI ns16550 device in ns16550_serial_probe().
This is still not perfect. If any PCI bus based ns16550 wrapper driver tries to access plat->base before calling probe(), it is still subject to break.
Fixes: 720f9e1fdb0c9 ("serial: ns16550: Move PCI access from ofdata_to_platdata() to probe()") Reported-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Signed-off-by: Bin Meng bmeng.cn@gmail.com Tested-by: Andy Shevchenko andriy.shevchenko@linux.intel.com Reviewed-by: Wolfgang Wallner wolfgang.wallner@br-automation.com Tested-by: Wolfgang Wallner wolfgang.wallner@br-automation.com
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Changes in v3: - extract the base address assignment to a helper
Changes in v2: - not to break Fixes, etc to two or more lines in the commit message - add the same CONFIG_SYS_NS16550_PORT_MAPPED ifdefs in the PCI case
drivers/serial/ns16550.c | 39 ++++++++++++++++++++++----------------- 1 file changed, 22 insertions(+), 17 deletions(-)
diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c index c1b303f..a2f1b35 100644 --- a/drivers/serial/ns16550.c +++ b/drivers/serial/ns16550.c @@ -479,39 +479,38 @@ static int ns16550_serial_getinfo(struct udevice *dev, return 0; }
-#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA) -static int ns1655_serial_set_base_addr(struct udevice *dev) +static int ns16550_serial_assign_base(struct ns16550_platdata *plat, ulong base) { - fdt_addr_t addr; - struct ns16550_platdata *plat; - - plat = dev_get_platdata(dev); - - addr = dev_read_addr_pci(dev); - if (addr == FDT_ADDR_T_NONE) + if (base == FDT_ADDR_T_NONE) return -EINVAL;
#ifdef CONFIG_SYS_NS16550_PORT_MAPPED - plat->base = addr; + plat->base = base; #else - plat->base = (unsigned long)map_physmem(addr, 0, MAP_NOCACHE); + plat->base = (unsigned long)map_physmem(base, 0, MAP_NOCACHE); #endif
return 0; } -#endif
int ns16550_serial_probe(struct udevice *dev) { + struct ns16550_platdata *plat = dev->platdata; struct NS16550 *const com_port = dev_get_priv(dev); struct reset_ctl_bulk reset_bulk; + fdt_addr_t addr; int ret;
-#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA) - ret = ns1655_serial_set_base_addr(dev); - if (ret) - return ret; -#endif + /* + * If we are on PCI bus, either directly attached to a PCI root port, + * or via a PCI bridge, assign platdata->base before probing hardware. + */ + if (device_is_on_pci_bus(dev)) { + addr = devfdt_get_addr_pci(dev); + ret = ns16550_serial_assign_base(plat, addr); + if (ret) + return ret; + }
ret = reset_get_bulk(dev, &reset_bulk); if (!ret) @@ -535,9 +534,15 @@ int ns16550_serial_ofdata_to_platdata(struct udevice *dev) { struct ns16550_platdata *plat = dev->platdata; const u32 port_type = dev_get_driver_data(dev); + fdt_addr_t addr; struct clk clk; int err;
+ addr = dev_read_addr(dev); + err = ns16550_serial_assign_base(plat, addr); + if (err && !device_is_on_pci_bus(dev)) + return err; + plat->reg_offset = dev_read_u32_default(dev, "reg-offset", 0); plat->reg_shift = dev_read_u32_default(dev, "reg-shift", 0); plat->reg_width = dev_read_u32_default(dev, "reg-io-width", 1);