On 02/01/2015 10:16 PM, Eddie Huang wrote:
> Hi Peter,
>
> On Sun, 2015-02-01 at 13:26 -0500, Peter Hurley wrote:
>> On 02/01/2015 11:27 AM, Peter Hurley wrote:
>>> Hi Eddie,
>>>
>>> On 01/12/2015 08:08 AM, Eddie Huang wrote:
>>>> Add earlycon support not only baudrate option, but also add noinit option.
>>>> If use noinit option, 8250 earlycon will not init serial hardware and use
>>>> loader setting.
>>>
>>> I see this went into Greg's tty-testing branch.
>>>
>>> The only point of this is to not program the divisor, right?
>>>
>>> I ask because early_serial8250_setup() could already handle this without
>>> extra options by simply not doing divisor programming if no baud option is
>>> present.
>>
>> Does the patch below work for your use-case?
>>
>> [ Note: the patch applies to 3.19-rcX. To test, your noinit patches need to be
>> reverted first.
>> ]
>>
>> --- >% ---
>> From: Peter Hurley <[email protected]>
>> Subject: [PATCH] serial: 8250_early: Assume uart already initialized if no
>> baud option
>>
>> The <baud><parity><bit> option string is not supplied if the earlycon
>> is started via devicetree and OF_EARLYCON_DECLARE(). The option string
>> is also not required if started via kernel command line parameters of
>> the form:
>> earlycon=uart,mmio,<addr>
>> console=uart,mmio,<addr>
>>
>> If earlycon_device->baud is 0, then an option string was not supplied.
>> In this case, assume the uart has already been initialized by the
>> bootloader or firmware.
>>
>> Signed-off-by: Peter Hurley <[email protected]>
>> ---
>> drivers/tty/serial/8250/8250_early.c | 10 ++++++++--
>> 1 file changed, 8 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c
>> index d7b831b..1701d00 100644
>> --- a/drivers/tty/serial/8250/8250_early.c
>> +++ b/drivers/tty/serial/8250/8250_early.c
>> @@ -149,12 +149,18 @@ static int __init early_serial8250_setup(struct earlycon_device *device,
>> return 0;
>>
>> if (!device->baud) {
>> + struct uart_port *port = &device->port;
>> + unsigned int ier;
>> +
>> device->baud = probe_baud(&device->port);
>> snprintf(device->options, sizeof(device->options), "%u",
>> device->baud);
>> - }
>>
>> - init_port(device);
>> + /* assume the device was initialized, only mask interrupts */
>> + ier = serial8250_early_in(port, UART_IER);
>> + serial8250_early_out(port, UART_IER, ier & UART_IER_UUE);
>> + } else
>> + init_port(device);
> Should add brace in else.
I don't do that unless I have to.
> Where is original line here.
> early_device = device;
Whoops :)
I wrote the patch from a private branch which implements extensible console
matching (so a console can define its own match function) and a bunch of
other console cleanup and code removal. In that series, early_device becomes
unnecessary and is removed.
I'll respin proper patches on top of Greg's tty-testing branch with reverts
for the noinit options. I noticed that one of the noinit patches actually
has the linkage for the mtk earlycon, so I'll be sure to preserve that.
Regards,
Peter Hurley
On Sun, Feb 01, 2015 at 10:45:12PM -0500, Peter Hurley wrote:
> On 02/01/2015 10:16 PM, Eddie Huang wrote:
> > Hi Peter,
> >
> > On Sun, 2015-02-01 at 13:26 -0500, Peter Hurley wrote:
> >> On 02/01/2015 11:27 AM, Peter Hurley wrote:
> >>> Hi Eddie,
> >>>
> >>> On 01/12/2015 08:08 AM, Eddie Huang wrote:
> >>>> Add earlycon support not only baudrate option, but also add noinit option.
> >>>> If use noinit option, 8250 earlycon will not init serial hardware and use
> >>>> loader setting.
> >>>
> >>> I see this went into Greg's tty-testing branch.
> >>>
> >>> The only point of this is to not program the divisor, right?
> >>>
> >>> I ask because early_serial8250_setup() could already handle this without
> >>> extra options by simply not doing divisor programming if no baud option is
> >>> present.
> >>
> >> Does the patch below work for your use-case?
> >>
> >> [ Note: the patch applies to 3.19-rcX. To test, your noinit patches need to be
> >> reverted first.
> >> ]
> >>
> >> --- >% ---
> >> From: Peter Hurley <[email protected]>
> >> Subject: [PATCH] serial: 8250_early: Assume uart already initialized if no
> >> baud option
> >>
> >> The <baud><parity><bit> option string is not supplied if the earlycon
> >> is started via devicetree and OF_EARLYCON_DECLARE(). The option string
> >> is also not required if started via kernel command line parameters of
> >> the form:
> >> earlycon=uart,mmio,<addr>
> >> console=uart,mmio,<addr>
> >>
> >> If earlycon_device->baud is 0, then an option string was not supplied.
> >> In this case, assume the uart has already been initialized by the
> >> bootloader or firmware.
> >>
> >> Signed-off-by: Peter Hurley <[email protected]>
> >> ---
> >> drivers/tty/serial/8250/8250_early.c | 10 ++++++++--
> >> 1 file changed, 8 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/tty/serial/8250/8250_early.c b/drivers/tty/serial/8250/8250_early.c
> >> index d7b831b..1701d00 100644
> >> --- a/drivers/tty/serial/8250/8250_early.c
> >> +++ b/drivers/tty/serial/8250/8250_early.c
> >> @@ -149,12 +149,18 @@ static int __init early_serial8250_setup(struct earlycon_device *device,
> >> return 0;
> >>
> >> if (!device->baud) {
> >> + struct uart_port *port = &device->port;
> >> + unsigned int ier;
> >> +
> >> device->baud = probe_baud(&device->port);
> >> snprintf(device->options, sizeof(device->options), "%u",
> >> device->baud);
> >> - }
> >>
> >> - init_port(device);
> >> + /* assume the device was initialized, only mask interrupts */
> >> + ier = serial8250_early_in(port, UART_IER);
> >> + serial8250_early_out(port, UART_IER, ier & UART_IER_UUE);
> >> + } else
> >> + init_port(device);
> > Should add brace in else.
>
> I don't do that unless I have to.
>
> > Where is original line here.
> > early_device = device;
>
> Whoops :)
>
> I wrote the patch from a private branch which implements extensible console
> matching (so a console can define its own match function) and a bunch of
> other console cleanup and code removal. In that series, early_device becomes
> unnecessary and is removed.
>
> I'll respin proper patches on top of Greg's tty-testing branch with reverts
> for the noinit options. I noticed that one of the noinit patches actually
> has the linkage for the mtk earlycon, so I'll be sure to preserve that.
I can just drop the patches in the tty-testing branch, that's what it is
there for :)
Just let me know the specific patches and I will do so, thanks.
greg k-h
On 02/01/2015 11:28 PM, Greg Kroah-Hartman wrote:
> On Sun, Feb 01, 2015 at 10:45:12PM -0500, Peter Hurley wrote:
>> On 02/01/2015 10:16 PM, Eddie Huang wrote:
>> I'll respin proper patches on top of Greg's tty-testing branch with reverts
>> for the noinit options. I noticed that one of the noinit patches actually
>> has the linkage for the mtk earlycon, so I'll be sure to preserve that.
>
> I can just drop the patches in the tty-testing branch, that's what it is
> there for :)
>
> Just let me know the specific patches and I will do so, thanks.
Well that pretty much means dropping the 3 patches that add earlycon to
8250_mtk and then applying my patch (needs fixed to apply cleanly, which
I can do) and then applying a fixed-up replacement patch to add earlycon
to 8250_mtk (which I can also supply).
Is that the way you want to go?
On Mon, Feb 02, 2015 at 12:15:31AM -0500, Peter Hurley wrote:
> On 02/01/2015 11:28 PM, Greg Kroah-Hartman wrote:
> > On Sun, Feb 01, 2015 at 10:45:12PM -0500, Peter Hurley wrote:
> >> On 02/01/2015 10:16 PM, Eddie Huang wrote:
>
> >> I'll respin proper patches on top of Greg's tty-testing branch with reverts
> >> for the noinit options. I noticed that one of the noinit patches actually
> >> has the linkage for the mtk earlycon, so I'll be sure to preserve that.
> >
> > I can just drop the patches in the tty-testing branch, that's what it is
> > there for :)
> >
> > Just let me know the specific patches and I will do so, thanks.
>
> Well that pretty much means dropping the 3 patches that add earlycon to
> 8250_mtk and then applying my patch (needs fixed to apply cleanly, which
> I can do) and then applying a fixed-up replacement patch to add earlycon
> to 8250_mtk (which I can also supply).
>
> Is that the way you want to go?
Sounds good to me, send your patch, and I'll fix it all up tomorrow.
thanks,
greg k-h