* [PATCH] serial: don't register CIR serial ports
@ 2015-08-05 12:33 Maciej S. Szmigiero
2015-08-05 14:51 ` Greg Kroah-Hartman
0 siblings, 1 reply; 4+ messages in thread
From: Maciej S. Szmigiero @ 2015-08-05 12:33 UTC (permalink / raw)
To: linux-serial; +Cc: Greg Kroah-Hartman, Jiri Slaby, linux-kernel
CIR type serial ports aren't real serial ports.
This is just a way to prevent legacy 8250 serial
driver from probing and eventually binding some
resources.
Since in current state such ports aren't providing
any real functionality and it is not possible
to change their type via setserial/ioctl(TIOCSSERIAL)
(due to UPF_FIXED_PORT flag set on them)
it is simpler and cleaner to not register them at all
with serial core.
Print a short message in this case so it is known
to user what has happened.
This way checks for PORT_8250_CIR in serial port
callbacks can be removed too, since they won't
ever be called.
Signed-off-by: Maciej Szmigiero <mail@maciej.szmigiero.name>
---
This replaces "serial: don't announce CIR serial ports"
submission.
drivers/tty/serial/8250/8250_core.c | 38 +++++++++++++++++-----------------
1 files changed, 19 insertions(+), 19 deletions(-)
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 37fff12..b843b83 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -2129,9 +2129,6 @@ int serial8250_do_startup(struct uart_port *port)
unsigned char lsr, iir;
int retval;
- if (port->type == PORT_8250_CIR)
- return -ENODEV;
-
if (!port->fifosize)
port->fifosize = uart_config[port->type].fifo_size;
if (!up->tx_loadsz)
@@ -2858,14 +2855,8 @@ static void serial8250_release_port(struct uart_port *port)
static int serial8250_request_port(struct uart_port *port)
{
struct uart_8250_port *up = up_to_u8250p(port);
- int ret;
-
- if (port->type == PORT_8250_CIR)
- return -ENODEV;
-
- ret = serial8250_request_std_resource(up);
- return ret;
+ return serial8250_request_std_resource(up);
}
static int fcr_get_rxtrig_bytes(struct uart_8250_port *up)
@@ -3013,9 +3004,6 @@ static void serial8250_config_port(struct uart_port *port, int flags)
struct uart_8250_port *up = up_to_u8250p(port);
int ret;
- if (port->type == PORT_8250_CIR)
- return;
-
/*
* Find the region that we can probe for. This in turn
* tells us whether we can probe for the type of port.
@@ -3889,13 +3877,25 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
if (up->dl_write)
uart->dl_write = up->dl_write;
- if (serial8250_isa_config != NULL)
- serial8250_isa_config(0, &uart->port,
- &uart->capabilities);
+ if (uart->port.type != PORT_8250_CIR) {
+ if (serial8250_isa_config != NULL)
+ serial8250_isa_config(0, &uart->port,
+ &uart->capabilities);
- ret = uart_add_one_port(&serial8250_reg, &uart->port);
- if (ret == 0)
- ret = uart->port.line;
+ ret = uart_add_one_port(&serial8250_reg,
+ &uart->port);
+ if (ret == 0)
+ ret = uart->port.line;
+ } else {
+ pr_info("%s%sskipping CIR port at 0x%lx / 0x%llx, IRQ %d\n",
+ uart->port.dev ? dev_name(uart->port.dev) : "",
+ uart->port.dev ? ": " : "",
+ uart->port.iobase,
+ (unsigned long long)uart->port.mapbase,
+ uart->port.irq);
+
+ ret = 0;
+ }
}
mutex_unlock(&serial_mutex);
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] serial: don't register CIR serial ports
2015-08-05 12:33 [PATCH] serial: don't register CIR serial ports Maciej S. Szmigiero
@ 2015-08-05 14:51 ` Greg Kroah-Hartman
2015-08-05 15:03 ` Maciej S. Szmigiero
0 siblings, 1 reply; 4+ messages in thread
From: Greg Kroah-Hartman @ 2015-08-05 14:51 UTC (permalink / raw)
To: Maciej S. Szmigiero; +Cc: linux-serial, Jiri Slaby, linux-kernel
On Wed, Aug 05, 2015 at 02:33:33PM +0200, Maciej S. Szmigiero wrote:
> CIR type serial ports aren't real serial ports.
>
> This is just a way to prevent legacy 8250 serial
> driver from probing and eventually binding some
> resources.
>
> Since in current state such ports aren't providing
> any real functionality and it is not possible
> to change their type via setserial/ioctl(TIOCSSERIAL)
> (due to UPF_FIXED_PORT flag set on them)
> it is simpler and cleaner to not register them at all
> with serial core.
>
> Print a short message in this case so it is known
> to user what has happened.
>
> This way checks for PORT_8250_CIR in serial port
> callbacks can be removed too, since they won't
> ever be called.
>
> Signed-off-by: Maciej Szmigiero <mail@maciej.szmigiero.name>
> ---
> This replaces "serial: don't announce CIR serial ports"
> submission.
>
> drivers/tty/serial/8250/8250_core.c | 38 +++++++++++++++++-----------------
> 1 files changed, 19 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
> index 37fff12..b843b83 100644
> --- a/drivers/tty/serial/8250/8250_core.c
> +++ b/drivers/tty/serial/8250/8250_core.c
> @@ -2129,9 +2129,6 @@ int serial8250_do_startup(struct uart_port *port)
> unsigned char lsr, iir;
> int retval;
>
> - if (port->type == PORT_8250_CIR)
> - return -ENODEV;
> -
> if (!port->fifosize)
> port->fifosize = uart_config[port->type].fifo_size;
> if (!up->tx_loadsz)
> @@ -2858,14 +2855,8 @@ static void serial8250_release_port(struct uart_port *port)
> static int serial8250_request_port(struct uart_port *port)
> {
> struct uart_8250_port *up = up_to_u8250p(port);
> - int ret;
> -
> - if (port->type == PORT_8250_CIR)
> - return -ENODEV;
> -
> - ret = serial8250_request_std_resource(up);
>
> - return ret;
> + return serial8250_request_std_resource(up);
> }
>
> static int fcr_get_rxtrig_bytes(struct uart_8250_port *up)
> @@ -3013,9 +3004,6 @@ static void serial8250_config_port(struct uart_port *port, int flags)
> struct uart_8250_port *up = up_to_u8250p(port);
> int ret;
>
> - if (port->type == PORT_8250_CIR)
> - return;
> -
> /*
> * Find the region that we can probe for. This in turn
> * tells us whether we can probe for the type of port.
> @@ -3889,13 +3877,25 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
> if (up->dl_write)
> uart->dl_write = up->dl_write;
>
> - if (serial8250_isa_config != NULL)
> - serial8250_isa_config(0, &uart->port,
> - &uart->capabilities);
> + if (uart->port.type != PORT_8250_CIR) {
> + if (serial8250_isa_config != NULL)
> + serial8250_isa_config(0, &uart->port,
> + &uart->capabilities);
>
> - ret = uart_add_one_port(&serial8250_reg, &uart->port);
> - if (ret == 0)
> - ret = uart->port.line;
> + ret = uart_add_one_port(&serial8250_reg,
> + &uart->port);
> + if (ret == 0)
> + ret = uart->port.line;
> + } else {
> + pr_info("%s%sskipping CIR port at 0x%lx / 0x%llx, IRQ %d\n",
> + uart->port.dev ? dev_name(uart->port.dev) : "",
> + uart->port.dev ? ": " : "",
> + uart->port.iobase,
> + (unsigned long long)uart->port.mapbase,
> + uart->port.irq);
dev_info() perhaps? It provides much of what you are trying to say
here.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] serial: don't register CIR serial ports
2015-08-05 14:51 ` Greg Kroah-Hartman
@ 2015-08-05 15:03 ` Maciej S. Szmigiero
2015-08-05 15:25 ` Greg Kroah-Hartman
0 siblings, 1 reply; 4+ messages in thread
From: Maciej S. Szmigiero @ 2015-08-05 15:03 UTC (permalink / raw)
To: Greg Kroah-Hartman; +Cc: linux-serial, Jiri Slaby, linux-kernel, Peter Hurley
On 05.08.2015 16:51, Greg Kroah-Hartman wrote:
> On Wed, Aug 05, 2015 at 02:33:33PM +0200, Maciej S. Szmigiero wrote:
>> CIR type serial ports aren't real serial ports.
>>
>> This is just a way to prevent legacy 8250 serial
>> driver from probing and eventually binding some
>> resources.
>>
>> Since in current state such ports aren't providing
>> any real functionality and it is not possible
>> to change their type via setserial/ioctl(TIOCSSERIAL)
>> (due to UPF_FIXED_PORT flag set on them)
>> it is simpler and cleaner to not register them at all
>> with serial core.
>>
>> Print a short message in this case so it is known
>> to user what has happened.
>>
>> This way checks for PORT_8250_CIR in serial port
>> callbacks can be removed too, since they won't
>> ever be called.
>>
>> Signed-off-by: Maciej Szmigiero <mail@maciej.szmigiero.name>
>> ---
>> This replaces "serial: don't announce CIR serial ports"
>> submission.
>>
>> drivers/tty/serial/8250/8250_core.c | 38 +++++++++++++++++-----------------
>> 1 files changed, 19 insertions(+), 19 deletions(-)
>>
>> diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
>> index 37fff12..b843b83 100644
>> --- a/drivers/tty/serial/8250/8250_core.c
>> +++ b/drivers/tty/serial/8250/8250_core.c
>> @@ -2129,9 +2129,6 @@ int serial8250_do_startup(struct uart_port *port)
>> unsigned char lsr, iir;
>> int retval;
>>
>> - if (port->type == PORT_8250_CIR)
>> - return -ENODEV;
>> -
>> if (!port->fifosize)
>> port->fifosize = uart_config[port->type].fifo_size;
>> if (!up->tx_loadsz)
>> @@ -2858,14 +2855,8 @@ static void serial8250_release_port(struct uart_port *port)
>> static int serial8250_request_port(struct uart_port *port)
>> {
>> struct uart_8250_port *up = up_to_u8250p(port);
>> - int ret;
>> -
>> - if (port->type == PORT_8250_CIR)
>> - return -ENODEV;
>> -
>> - ret = serial8250_request_std_resource(up);
>>
>> - return ret;
>> + return serial8250_request_std_resource(up);
>> }
>>
>> static int fcr_get_rxtrig_bytes(struct uart_8250_port *up)
>> @@ -3013,9 +3004,6 @@ static void serial8250_config_port(struct uart_port *port, int flags)
>> struct uart_8250_port *up = up_to_u8250p(port);
>> int ret;
>>
>> - if (port->type == PORT_8250_CIR)
>> - return;
>> -
>> /*
>> * Find the region that we can probe for. This in turn
>> * tells us whether we can probe for the type of port.
>> @@ -3889,13 +3877,25 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
>> if (up->dl_write)
>> uart->dl_write = up->dl_write;
>>
>> - if (serial8250_isa_config != NULL)
>> - serial8250_isa_config(0, &uart->port,
>> - &uart->capabilities);
>> + if (uart->port.type != PORT_8250_CIR) {
>> + if (serial8250_isa_config != NULL)
>> + serial8250_isa_config(0, &uart->port,
>> + &uart->capabilities);
>>
>> - ret = uart_add_one_port(&serial8250_reg, &uart->port);
>> - if (ret == 0)
>> - ret = uart->port.line;
>> + ret = uart_add_one_port(&serial8250_reg,
>> + &uart->port);
>> + if (ret == 0)
>> + ret = uart->port.line;
>> + } else {
>> + pr_info("%s%sskipping CIR port at 0x%lx / 0x%llx, IRQ %d\n",
>> + uart->port.dev ? dev_name(uart->port.dev) : "",
>> + uart->port.dev ? ": " : "",
>> + uart->port.iobase,
>> + (unsigned long long)uart->port.mapbase,
>> + uart->port.irq);
>
> dev_info() perhaps? It provides much of what you are trying to say
> here.
I thought about it, but while currently uart->port.dev is always set
(because these ports are "registered" by PNP 8250 driver) maybe
one day other sources will also make use of this port type.
Then dev_info() will result in "(NULL device *): " prefix.
That's why it is a similar construct as in uart_report_port() to
skip device name altogether in such case.
Best regards,
Maciej Szmigiero
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] serial: don't register CIR serial ports
2015-08-05 15:03 ` Maciej S. Szmigiero
@ 2015-08-05 15:25 ` Greg Kroah-Hartman
0 siblings, 0 replies; 4+ messages in thread
From: Greg Kroah-Hartman @ 2015-08-05 15:25 UTC (permalink / raw)
To: Maciej S. Szmigiero; +Cc: linux-serial, Jiri Slaby, linux-kernel, Peter Hurley
On Wed, Aug 05, 2015 at 05:03:50PM +0200, Maciej S. Szmigiero wrote:
> On 05.08.2015 16:51, Greg Kroah-Hartman wrote:
> > On Wed, Aug 05, 2015 at 02:33:33PM +0200, Maciej S. Szmigiero wrote:
> >> CIR type serial ports aren't real serial ports.
> >>
> >> This is just a way to prevent legacy 8250 serial
> >> driver from probing and eventually binding some
> >> resources.
> >>
> >> Since in current state such ports aren't providing
> >> any real functionality and it is not possible
> >> to change their type via setserial/ioctl(TIOCSSERIAL)
> >> (due to UPF_FIXED_PORT flag set on them)
> >> it is simpler and cleaner to not register them at all
> >> with serial core.
> >>
> >> Print a short message in this case so it is known
> >> to user what has happened.
> >>
> >> This way checks for PORT_8250_CIR in serial port
> >> callbacks can be removed too, since they won't
> >> ever be called.
> >>
> >> Signed-off-by: Maciej Szmigiero <mail@maciej.szmigiero.name>
> >> ---
> >> This replaces "serial: don't announce CIR serial ports"
> >> submission.
> >>
> >> drivers/tty/serial/8250/8250_core.c | 38 +++++++++++++++++-----------------
> >> 1 files changed, 19 insertions(+), 19 deletions(-)
> >>
> >> diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
> >> index 37fff12..b843b83 100644
> >> --- a/drivers/tty/serial/8250/8250_core.c
> >> +++ b/drivers/tty/serial/8250/8250_core.c
> >> @@ -2129,9 +2129,6 @@ int serial8250_do_startup(struct uart_port *port)
> >> unsigned char lsr, iir;
> >> int retval;
> >>
> >> - if (port->type == PORT_8250_CIR)
> >> - return -ENODEV;
> >> -
> >> if (!port->fifosize)
> >> port->fifosize = uart_config[port->type].fifo_size;
> >> if (!up->tx_loadsz)
> >> @@ -2858,14 +2855,8 @@ static void serial8250_release_port(struct uart_port *port)
> >> static int serial8250_request_port(struct uart_port *port)
> >> {
> >> struct uart_8250_port *up = up_to_u8250p(port);
> >> - int ret;
> >> -
> >> - if (port->type == PORT_8250_CIR)
> >> - return -ENODEV;
> >> -
> >> - ret = serial8250_request_std_resource(up);
> >>
> >> - return ret;
> >> + return serial8250_request_std_resource(up);
> >> }
> >>
> >> static int fcr_get_rxtrig_bytes(struct uart_8250_port *up)
> >> @@ -3013,9 +3004,6 @@ static void serial8250_config_port(struct uart_port *port, int flags)
> >> struct uart_8250_port *up = up_to_u8250p(port);
> >> int ret;
> >>
> >> - if (port->type == PORT_8250_CIR)
> >> - return;
> >> -
> >> /*
> >> * Find the region that we can probe for. This in turn
> >> * tells us whether we can probe for the type of port.
> >> @@ -3889,13 +3877,25 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
> >> if (up->dl_write)
> >> uart->dl_write = up->dl_write;
> >>
> >> - if (serial8250_isa_config != NULL)
> >> - serial8250_isa_config(0, &uart->port,
> >> - &uart->capabilities);
> >> + if (uart->port.type != PORT_8250_CIR) {
> >> + if (serial8250_isa_config != NULL)
> >> + serial8250_isa_config(0, &uart->port,
> >> + &uart->capabilities);
> >>
> >> - ret = uart_add_one_port(&serial8250_reg, &uart->port);
> >> - if (ret == 0)
> >> - ret = uart->port.line;
> >> + ret = uart_add_one_port(&serial8250_reg,
> >> + &uart->port);
> >> + if (ret == 0)
> >> + ret = uart->port.line;
> >> + } else {
> >> + pr_info("%s%sskipping CIR port at 0x%lx / 0x%llx, IRQ %d\n",
> >> + uart->port.dev ? dev_name(uart->port.dev) : "",
> >> + uart->port.dev ? ": " : "",
> >> + uart->port.iobase,
> >> + (unsigned long long)uart->port.mapbase,
> >> + uart->port.irq);
> >
> > dev_info() perhaps? It provides much of what you are trying to say
> > here.
>
> I thought about it, but while currently uart->port.dev is always set
> (because these ports are "registered" by PNP 8250 driver) maybe
> one day other sources will also make use of this port type.
Let someone in the future worry about that, right now the structure is
always there, so please use it.
greg k-h
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2015-08-05 15:25 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2015-08-05 12:33 [PATCH] serial: don't register CIR serial ports Maciej S. Szmigiero
2015-08-05 14:51 ` Greg Kroah-Hartman
2015-08-05 15:03 ` Maciej S. Szmigiero
2015-08-05 15:25 ` Greg Kroah-Hartman
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