On Fri, Apr 03, 2020 at 06:35:32PM -0700, Bin Meng wrote:

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

And re-tested. Works for me, thanks!

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

---

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);

-- 2.7.4