[PATCH v6 0/3] serial: 8250_pnp: Support configurable reg shift property

[PATCH v6 0/3] serial: 8250_pnp: Support configurable reg shift property

[Guanbing Huang]

From: Guanbing Huang <albanhuang@tencent.com>

The 16550a serial port based on the ACPI table requires obtaining the
reg-shift attribute. In the ACPI scenario, If the reg-shift property
is not configured like in DTS, the 16550a serial driver cannot read or
write controller registers properly during initialization.

To address the issue of configuring the reg-shift property, the 
__uart_read_properties() universal interface is called to implement it.
Adaptation of PNP devices is done in the __uart_read_properties() function.

Guanbing Huang (3):
  PNP: Add dev_is_pnp() macro
  serial: port: Add support of PNP IRQ to __uart_read_properties()
  serial: 8250_pnp: Support configurable reg shift property

 drivers/tty/serial/8250/8250_pnp.c | 40 +++++++++++++++++++-----------
 drivers/tty/serial/serial_port.c   |  7 +++++-
 include/linux/pnp.h                |  2 ++
 3 files changed, 33 insertions(+), 16 deletions(-)

-- 
2.17.1

[PATCH v6 1/3] PNP: Add dev_is_pnp() macro

[Guanbing Huang]

From: Guanbing Huang <albanhuang@tencent.com>

Add dev_is_pnp() macro to determine whether the device is a PNP device.

Signed-off-by: Guanbing Huang <albanhuang@tencent.com>
Suggested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Reviewed-by: Bing Fan <tombinfan@tencent.com>
Tested-by: Linheng Du <dylanlhdu@tencent.com>
---
v5 -> v6: fix the issue that the cover letter is not chained with the patch series
v4 -> v5: change "pnp" in the commit message to uppercase

 include/linux/pnp.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/pnp.h b/include/linux/pnp.h
index ddbe7c3ca4ce..792921c06594 100644
--- a/include/linux/pnp.h
+++ b/include/linux/pnp.h
@@ -502,6 +502,8 @@ static inline void pnp_unregister_driver(struct pnp_driver *drv) { }
 
 #endif /* CONFIG_PNP */
 
+#define dev_is_pnp(d) ((d)->bus == &pnp_bus_type)
+
 /**
  * module_pnp_driver() - Helper macro for registering a PnP driver
  * @__pnp_driver: pnp_driver struct
-- 
2.17.1

[PATCH v6 2/3] serial: port: Add support of PNP IRQ to __uart_read_properties()

[Guanbing Huang]

From: Guanbing Huang <albanhuang@tencent.com>

The function __uart_read_properties doesn't cover PNP devices, so add IRQ
processing for PNP devices in the branch.

Signed-off-by: Guanbing Huang <albanhuang@tencent.com>
Suggested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Reviewed-by: Bing Fan <tombinfan@tencent.com>
Tested-by: Linheng Du <dylanlhdu@tencent.com>
---
v5 -> v6: fix the issue that the cover letter is not chained with the patch series
v4 -> v5: change "pnp" and "irq" in the commit message to uppercase, modify the subject
          to start with "serial: port:", modify the location of the header file pnp.h 

 drivers/tty/serial/serial_port.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/serial_port.c b/drivers/tty/serial/serial_port.c
index 22b9eeb23e68..8504bae1d2c9 100644
--- a/drivers/tty/serial/serial_port.c
+++ b/drivers/tty/serial/serial_port.c
@@ -11,6 +11,7 @@
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/pnp.h>
 #include <linux/property.h>
 #include <linux/serial_core.h>
 #include <linux/spinlock.h>
@@ -221,7 +222,11 @@ static int __uart_read_properties(struct uart_port *port, bool use_defaults)
 
 	if (dev_is_platform(dev))
 		ret = platform_get_irq(to_platform_device(dev), 0);
-	else
+	else if (dev_is_pnp(dev)) {
+		ret = pnp_irq(to_pnp_dev(dev), 0);
+		if (ret < 0)
+			ret = -ENXIO;
+	} else
 		ret = fwnode_irq_get(dev_fwnode(dev), 0);
 	if (ret == -EPROBE_DEFER)
 		return ret;
-- 
2.17.1

Re: [PATCH v6 2/3] serial: port: Add support of PNP IRQ to __uart_read_properties()

[kernel test robot]

Hi Guanbing,

kernel test robot noticed the following build errors:

[auto build test ERROR on tty/tty-testing]
[also build test ERROR on tty/tty-next tty/tty-linus usb/usb-testing usb/usb-next usb/usb-linus linus/master v6.9-rc3 next-20240409]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Guanbing-Huang/PNP-Add-dev_is_pnp-macro/20240409-154558
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing
patch link:    https://lore.kernel.org/r/e6dc33e399f119e6430bca48223cb2127930939b.1712646750.git.albanhuang%40tencent.com
patch subject: [PATCH v6 2/3] serial: port: Add support of PNP IRQ to __uart_read_properties()
config: sparc-allnoconfig (https://download.01.org/0day-ci/archive/20240410/202404100548.rbAa11Xr-lkp@intel.com/config)
compiler: sparc-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240410/202404100548.rbAa11Xr-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202404100548.rbAa11Xr-lkp@intel.com/

All errors (new ones prefixed by >>):

   sparc-linux-ld: drivers/tty/serial/serial_port.o: in function `__uart_read_properties':
   serial_port.c:(.text+0x1c4): undefined reference to `pnp_bus_type'
>> sparc-linux-ld: serial_port.c:(.text+0x1c8): undefined reference to `pnp_bus_type'

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH v6 2/3] serial: port: Add support of PNP IRQ to __uart_read_properties()

[kernel test robot]

Hi Guanbing,

kernel test robot noticed the following build errors:

[auto build test ERROR on tty/tty-testing]
[also build test ERROR on tty/tty-next tty/tty-linus usb/usb-testing usb/usb-next usb/usb-linus linus/master v6.9-rc3 next-20240409]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Guanbing-Huang/PNP-Add-dev_is_pnp-macro/20240409-154558
base:   https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing
patch link:    https://lore.kernel.org/r/e6dc33e399f119e6430bca48223cb2127930939b.1712646750.git.albanhuang%40tencent.com
patch subject: [PATCH v6 2/3] serial: port: Add support of PNP IRQ to __uart_read_properties()
config: openrisc-defconfig (https://download.01.org/0day-ci/archive/20240410/202404100523.b06UvPSB-lkp@intel.com/config)
compiler: or1k-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240410/202404100523.b06UvPSB-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202404100523.b06UvPSB-lkp@intel.com/

All errors (new ones prefixed by >>):

   or1k-linux-ld: drivers/tty/serial/serial_port.o: in function `__uart_read_properties':
>> serial_port.c:(.text+0x230): undefined reference to `pnp_bus_type'
>> or1k-linux-ld: serial_port.c:(.text+0x234): undefined reference to `pnp_bus_type'

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

[PATCH v6 3/3] serial: 8250_pnp: Support configurable reg shift property

[Guanbing Huang]

From: Guanbing Huang <albanhuang@tencent.com>

The 16550a serial port based on the ACPI table requires obtaining the
reg-shift attribute. In the ACPI scenario, If the reg-shift property
is not configured like in DTS, the 16550a serial driver cannot read or
write controller registers properly during initialization.

Signed-off-by: Guanbing Huang <albanhuang@tencent.com>
Suggested-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Reviewed-by: Bing Fan <tombinfan@tencent.com>
Tested-by: Linheng Du <dylanlhdu@tencent.com>
---
v5 -> v6: fix the issue that the cover letter is not chained with the patch series
v4 -> v5: modify to obtain the value of mapsize through the pnp_mem_len function,
          add annotations for the iotype variable, delete excess uart.port.flags operation
v3 -> v4: dependent on two pre patches: "pnp: Add dev_is_pnp() macro" and
          "serial: 8250_port: Add support of pnp irq to  __uart_read_properties()",
          the iotype is reserved, the mapsize is initialized, fix the UPF_SHARE_IRQ
	  flag, check for IRQ being absent
v2 -> v3: switch to use uart_read_port_properties(), change "Signed-off-by" to "Reviewed-by" and "Tested-by"
v1 -> v2: change the names after "Signed off by" to the real names

 drivers/tty/serial/8250/8250_pnp.c | 40 +++++++++++++++++++-----------
 1 file changed, 25 insertions(+), 15 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_pnp.c b/drivers/tty/serial/8250/8250_pnp.c
index 1974bbadc975..8f72a7de1d1d 100644
--- a/drivers/tty/serial/8250/8250_pnp.c
+++ b/drivers/tty/serial/8250/8250_pnp.c
@@ -435,6 +435,7 @@ serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 {
 	struct uart_8250_port uart, *port;
 	int ret, line, flags = dev_id->driver_data;
+	unsigned char iotype;
 
 	if (flags & UNKNOWN_DEV) {
 		ret = serial_pnp_guess_board(dev);
@@ -443,37 +444,46 @@ serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 	}
 
 	memset(&uart, 0, sizeof(uart));
-	if (pnp_irq_valid(dev, 0))
-		uart.port.irq = pnp_irq(dev, 0);
 	if ((flags & CIR_PORT) && pnp_port_valid(dev, 2)) {
 		uart.port.iobase = pnp_port_start(dev, 2);
-		uart.port.iotype = UPIO_PORT;
+		iotype = UPIO_PORT;
 	} else if (pnp_port_valid(dev, 0)) {
 		uart.port.iobase = pnp_port_start(dev, 0);
-		uart.port.iotype = UPIO_PORT;
+		iotype = UPIO_PORT;
 	} else if (pnp_mem_valid(dev, 0)) {
 		uart.port.mapbase = pnp_mem_start(dev, 0);
-		uart.port.iotype = UPIO_MEM;
+		uart.port.mapsize = pnp_mem_len(dev, 0);
+		iotype = UPIO_MEM;
 		uart.port.flags = UPF_IOREMAP;
 	} else
 		return -ENODEV;
 
-	dev_dbg(&dev->dev,
-		 "Setup PNP port: port %#lx, mem %#llx, irq %u, type %u\n",
-		 uart.port.iobase, (unsigned long long)uart.port.mapbase,
-		 uart.port.irq, uart.port.iotype);
+	uart.port.uartclk = 1843200;
+	uart.port.dev = &dev->dev;
+	uart.port.flags |= UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;
+
+	ret = uart_read_port_properties(&uart.port);
+	/* no interrupt -> fall back to polling */
+	if (ret == -ENXIO)
+		ret = 0;
+	if (ret)
+		return ret;
+
+	/*
+	 * The previous call may not set iotype correctly when reg-io-width
+	 * property is absent and it doesn't support IO port resource.
+	 */
+	uart.port.iotype = iotype;
 
 	if (flags & CIR_PORT) {
 		uart.port.flags |= UPF_FIXED_PORT | UPF_FIXED_TYPE;
 		uart.port.type = PORT_8250_CIR;
 	}
 
-	uart.port.flags |= UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;
-	if (pnp_irq_flags(dev, 0) & IORESOURCE_IRQ_SHAREABLE)
-		uart.port.flags |= UPF_SHARE_IRQ;
-	uart.port.uartclk = 1843200;
-	device_property_read_u32(&dev->dev, "clock-frequency", &uart.port.uartclk);
-	uart.port.dev = &dev->dev;
+	dev_dbg(&dev->dev,
+		 "Setup PNP port: port %#lx, mem %#llx, size %#llx, irq %u, type %u\n",
+		 uart.port.iobase, (unsigned long long)uart.port.mapbase,
+		 (unsigned long long)uart.port.mapsize, uart.port.irq, uart.port.iotype);
 
 	line = serial8250_register_8250_port(&uart);
 	if (line < 0 || (flags & CIR_PORT))
-- 
2.17.1

Re: [PATCH v6 0/3] serial: 8250_pnp: Support configurable reg shift property

[Andy Shevchenko]

On Tue, Apr 09, 2024 at 03:43:20PM +0800, Guanbing Huang wrote:
> From: Guanbing Huang <albanhuang@tencent.com>
> 
> The 16550a serial port based on the ACPI table requires obtaining the
> reg-shift attribute. In the ACPI scenario, If the reg-shift property
> is not configured like in DTS, the 16550a serial driver cannot read or
> write controller registers properly during initialization.
> 
> To address the issue of configuring the reg-shift property, the 
> __uart_read_properties() universal interface is called to implement it.
> Adaptation of PNP devices is done in the __uart_read_properties() function.

You either forgot or deliberately not added my tag. Can you elaborate?

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v6 0/3] serial: 8250_pnp: Support configurable reg shift property

[albanhuang]

在 2024/4/9 20:53, Andy Shevchenko 写道:
> On Tue, Apr 09, 2024 at 03:43:20PM +0800, Guanbing Huang wrote:
>> From: Guanbing Huang <albanhuang@tencent.com>
>>
>> The 16550a serial port based on the ACPI table requires obtaining the
>> reg-shift attribute. In the ACPI scenario, If the reg-shift property
>> is not configured like in DTS, the 16550a serial driver cannot read or
>> write controller registers properly during initialization.
>>
>> To address the issue of configuring the reg-shift property, the
>> __uart_read_properties() universal interface is called to implement it.
>> Adaptation of PNP devices is done in the __uart_read_properties() function.
> You either forgot or deliberately not added my tag. Can you elaborate?

I'm very sorry, this is my first time submitting a kernel patch. My 
understanding

of the submission specification is not comprehensive and profound enough,

and I didn't intentionally not add tags. I hope you can forgive my 
operational mistake.

Should I just add a "Reviewed-by tag", or do I need any other tags? Thanks.


With Best Regards.

>

Re: [PATCH v6 0/3] serial: 8250_pnp: Support configurable reg shift property

[Andy Shevchenko]

On Wed, Apr 10, 2024 at 10:49:29AM +0800, albanhuang wrote:
> 在 2024/4/9 20:53, Andy Shevchenko 写道:
> > On Tue, Apr 09, 2024 at 03:43:20PM +0800, Guanbing Huang wrote:
> > > From: Guanbing Huang <albanhuang@tencent.com>
> > > 
> > > The 16550a serial port based on the ACPI table requires obtaining the
> > > reg-shift attribute. In the ACPI scenario, If the reg-shift property
> > > is not configured like in DTS, the 16550a serial driver cannot read or
> > > write controller registers properly during initialization.
> > > 
> > > To address the issue of configuring the reg-shift property, the
> > > __uart_read_properties() universal interface is called to implement it.
> > > Adaptation of PNP devices is done in the __uart_read_properties() function.
> > You either forgot or deliberately not added my tag. Can you elaborate?
> 
> I'm very sorry, this is my first time submitting a kernel patch. My
> understanding
> 
> of the submission specification is not comprehensive and profound enough,
> 
> and I didn't intentionally not add tags. I hope you can forgive my
> operational mistake.
> 
> Should I just add a "Reviewed-by tag", or do I need any other tags? Thanks.

Understood. So if you are is one who is sending a new version, you should take
care about any given tags (such as Reviewed-by) and carry them, in case the
code is not drastically changed. I.o.w. if you don't, you have to explain why.

Anyways, it seems the patch still has a flaw as per LKP, so fix that by
providing probably two macros in the pnp.h header for both cases
(CONFIG_PNP=y/n), and I will review it again.

	#ifdef CONFIG_PNP
	...
	#define dev_is_pnp(...) ...
	...
	#else
	...
	#define dev_is_pnp(...)		false
	...
	#endif

-- 
With Best Regards,
Andy Shevchenko