[PATCH] serial: samsung: Fix serial config dependencies for exynos7

[Abhilash Kesavan]

Hello Greg,

On Mon, Nov 17, 2014 at 2:40 AM, gregkh at linuxfoundation.org
<gregkh at linuxfoundation.org> wrote:
> On Sun, Nov 16, 2014 at 07:47:02AM +0530, Abhilash Kesavan wrote:
>> Hello Greg,
>>
>> On Tue, Nov 11, 2014 at 7:55 PM, Abhilash Kesavan
>> <kesavan.abhilash at gmail.com> wrote:
>> > Hi Greg,
>> >
>> > On Tue, Sep 30, 2014 at 8:02 PM, Abhilash Kesavan
>> > <kesavan.abhilash at gmail.com> wrote:
>> >> Hi Tomasz,
>> >>
>> >> On Tue, Sep 30, 2014 at 4:08 AM, Tomasz Figa <tomasz.figa at gmail.com> wrote:
>> >>> Hi Abhilash,
>> >>>
>> >>> The patch itself seems fine, but I wonder if those config options aren't
>> >>> really just leftovers from the past and couldn't be completely removed.
>> >>>
>> >>> On 29.09.2014 07:16, Abhilash Kesavan wrote:
>> >>>> From: Pankaj Dubey <pankaj.dubey at samsung.com>
>> >>>>
>> >>>> Exynos7 has a similar serial controller to that present in older Samsung
>> >>>> SoCs. To re-use the existing serial driver on Exynos7 we need to have
>> >>>> SERIAL_SAMSUNG_UARTS_4 and SERIAL_SAMSUNG_UARTS selected. This is not
>> >>>> possible because these symbols are dependent on PLAT_SAMSUNG which is
>> >>>> not present for the ARMv8 based exynos7.
>> >>>>
>> >>>> Change the dependency of these symbols from PLAT_SAMSUNG to the serial
>> >>>> driver thus making it available on exynos7. As the existing platform
>> >>>> specific code making use of these symbols is related to uart driver this
>> >>>> change in dependency should not cause any issues.
>> >>>>
>> >>>> Signed-off-by: Pankaj Dubey <pankaj.dubey at samsung.com>
>> >>>> Signed-off-by: Naveen Krishna Chatradhi <ch.naveen at samsung.com>
>> >>>> Signed-off-by: Abhilash Kesavan <a.kesavan at samsung.com>
>> >>>> Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
>> >>>> ---
>> >>>> Build tested with s3c6400_defconfig, exynos_defconfig and arm64's defconfig
>> >>>> with and without the serial driver enabled.
>> >>>>
>> >>>>  drivers/tty/serial/Kconfig |    4 ++--
>> >>>>  1 file changed, 2 insertions(+), 2 deletions(-)
>> >>>>
>> >>>> diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
>> >>>> index 81f6ee7..e6c0bcb 100644
>> >>>> --- a/drivers/tty/serial/Kconfig
>> >>>> +++ b/drivers/tty/serial/Kconfig
>> >>>> @@ -249,14 +249,14 @@ config SERIAL_SAMSUNG
>> >>>>
>> >>>>  config SERIAL_SAMSUNG_UARTS_4
>> >>>>       bool
>> >>>> -     depends on PLAT_SAMSUNG
>> >>>> +     depends on SERIAL_SAMSUNG
>> >>>>       default y if !(CPU_S3C2410 || CPU_S3C2412 || CPU_S3C2440 || CPU_S3C2442)
>> >>>>       help
>> >>>>         Internal node for the common case of 4 Samsung compatible UARTs
>> >>>
>> >>> The only place where this symbol is used is below.
>> >>>
>> >>>>
>> >>>>  config SERIAL_SAMSUNG_UARTS
>> >>>>       int
>> >>>> -     depends on PLAT_SAMSUNG
>> >>>> +     depends on SERIAL_SAMSUNG
>> >>>>       default 4 if SERIAL_SAMSUNG_UARTS_4 || CPU_S3C2416
>> >>>>       default 3
>> >>>>       help
>> >>>>
>> >>>
>> >>> With this symbol the situation isn't that easy, but still should be
>> >>> manageable.
>> >>>
>> >>> Looking at the serial-samsung driver, all occurrences of
>> >>> CONFIG_SERIAL_SAMSUNG_UARTS could be simply replaced with a locally
>> >>> defined number equal to the maximum value - in this case 4.
>> >>>
>> >>> There are also two places in arch/arm where this symbol is used:
>> >>>
>> >>> 1) In arch/arm/mach-s3c64xx/irq-pm.c it's used as the number of serial
>> >>> ports which need suspend/resume handling. Since on s3c64xx the number is
>> >>> always 4, it can be simply defined locally as a constant.
>> >>>
>> >>> 2) In arch/arm/plat-samsung/init.c it is used to determine size of a
>> >>> static array of UART ports and to check whether the UART driver is
>> >>> enabled. In former case I believe it should be safe to hardcode it to 4
>> >>> as well, in latter CONFIG_SERIAL_SAMSUNG can be used.
>> >>
>> >> I will post patches removing these two symbols.
>> >
>> > I posted a couple of patches handling Tomasz' comments but Kukjin
>> > prefers the approach in this patch (Discussion here:
>> > http://www.spinics.net/lists/linux-samsung-soc/msg38742.html).
>> > Can you please review the patch.
>>
>> This is a gentle reminder. The patch is required for serial enablement
>> on the new exynos7 SoC, kindly take a look.
>
> What patch?  I fail to see anything in my inboxes that I can apply, only
> this long thread that makes no sense at all.
>
> Please resend anything that you want to have applied, in a format that I
> can apply it, _AND_ get everyone to agree that it is the correct
> solution.
>
> Asking me to go look up random web archives, of mailing list threads I
> was never copied on, is a sure way to get your email ignored, as again,
> there is nothing I can do with it.  You know better than this.

Apologies for the patch not reaching you. I will re-send it right now.
Kukjin Kim has already approved the approach under discussion; however
the patch needs to go via Kukjin's tree due to other patches that
depend on it. Hence, I require your ack on it.

Once again, sorry for the inconvenience.

Thanks,
Abhilash