diff mbox series

[v3] serial: ns16550: Fix ordering of getting base address

Message ID 1585964132-5831-1-git-send-email-bmeng.cn@gmail.com
State Accepted
Commit 9e6ce62190b7cd874d2bf727c7681292551ba6b9
Delegated to: Bin Meng
Headers show
Series [v3] serial: ns16550: Fix ordering of getting base address | expand

Commit Message

Bin Meng April 4, 2020, 1:35 a.m. UTC
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>

---

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(-)

Comments

Andy Shevchenko April 4, 2020, 10:32 a.m. UTC | #1
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
>
Bin Meng April 4, 2020, 2:14 p.m. UTC | #2
On Sat, Apr 4, 2020 at 6:32 PM Andy Shevchenko
<andriy.shevchenko@linux.intel.com> wrote:
>
> 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>
> >

applied to u-boot-x86, thanks!
Wolfgang Wallner April 6, 2020, 7:08 a.m. UTC | #3
Hi Bin,

-----"Bin Meng" <bmeng.cn@gmail.com> schrieb: -----

>On Sat, Apr 4, 2020 at 6:32 PM Andy Shevchenko
><andriy.shevchenko@linux.intel.com> wrote:
>>
>> 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>
>> >
>
>applied to u-boot-x86, thanks!
>

Maybe a little late, but I have also re-tested v3 now and can
confirm it still works, thanks!

regards, Wolfgang
Bin Meng April 6, 2020, 7:36 a.m. UTC | #4
Hi Wolfgang,

On Mon, Apr 6, 2020 at 3:08 PM Wolfgang Wallner
<wolfgang.wallner@br-automation.com> wrote:
>
> Hi Bin,
>
> -----"Bin Meng" <bmeng.cn@gmail.com> schrieb: -----
>
> >On Sat, Apr 4, 2020 at 6:32 PM Andy Shevchenko
> ><andriy.shevchenko@linux.intel.com> wrote:
> >>
> >> 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>
> >> >
> >
> >applied to u-boot-x86, thanks!
> >
>
> Maybe a little late, but I have also re-tested v3 now and can
> confirm it still works, thanks!
>

Thank you. The fix is now in the mainline.

Regards,
Bin
diff mbox series

Patch

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);