2011-05-29 09:22:08

by Toralf Förster

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Subject: 2 small kernel config issues related to UML + RTC

Hello,

with the current git kernel I run
$>make ARCH=um menuconfig

and searched for the string "RTC" b/c during boot of my UML image I realized nowadays the message:

"Kernel not built with RTC support, ALARM timers will not wake from suspend"

Although the menuconfig gives me the answer :

│ Symbol: STMMAC_RTC_TIMER [=n] │
│ Type : boolean │
│ Prompt: Real time clock │
│ Defined at drivers/net/stmmac/Kconfig:50 │
│ Depends on: <choice> && RTC_CLASS │
│ Location: │
│ -> Network device support (NETDEVICES [=y]) │
│ -> Ethernet (1000 Mbit) (NETDEV_1000 [=n]) │
│ -> STMicroelectronics 10/100/1000 Ethernet driver (STMMAC_ETH [=n]) │
│ -> STMMAC Timer optimisation (STMMAC_TIMER [=n]) │
│ -> Select Timer device (<choice> [=n]) │


I cannot found the menu item.

To sum it up IMO the kernel mesage doesn't makes sense for UML
and furthermore searching for "RTC" shouldn't give non-existent menu items, isn't it ?


--
MfG/Sincerely
Toralf Förster
pgp finger print: 7B1A 07F4 EC82 0F90 D4C2 8936 872A E508 7DB6 9DA3


2011-05-29 09:54:27

by Richard Weinberger

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Subject: Re: 2 small kernel config issues related to UML + RTC

2011/5/29 Toralf Förster <[email protected]>:
> Hello,
>
> with the current git kernel I run
> $>make ARCH=um menuconfig
>
> and searched for the string "RTC" b/c during boot of my UML image I realized nowadays the message:
>
> "Kernel not built with RTC support, ALARM timers will not wake from suspend"
>
> Although the menuconfig gives me the answer :
>
>  │ Symbol: STMMAC_RTC_TIMER [=n]                                                                                   │
>  │ Type  : boolean                                                                                                 │
>  │ Prompt: Real time clock                                                                                         │
>  │   Defined at drivers/net/stmmac/Kconfig:50                                                                      │
>  │   Depends on: <choice> && RTC_CLASS                                                                             │
>  │   Location:                                                                                                     │
>  │     -> Network device support (NETDEVICES [=y])                                                                 │
>  │       -> Ethernet (1000 Mbit) (NETDEV_1000 [=n])                                                                │
>  │         -> STMicroelectronics 10/100/1000 Ethernet driver (STMMAC_ETH [=n])                                     │
>  │           -> STMMAC Timer optimisation (STMMAC_TIMER [=n])                                                      │
>  │             -> Select Timer device (<choice> [=n])                                                              │
>
>
> I cannot found the menu item.
>
> To sum it up IMO the kernel mesage doesn't makes sense for UML
> and furthermore searching for "RTC" shouldn't give non-existent menu items, isn't it ?

I saw this message too.
A fix is on the way...

--
Thanks,
//richard
????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?

2011-05-29 17:18:13

by Valdis Klētnieks

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Subject: Re: 2 small kernel config issues related to UML + RTC

On Sun, 29 May 2011 11:22:01 +0200, Toralf F?rster said:
> │ Symbol: STMMAC_RTC_TIMER [=n]
> │ Type : boolean
> │ Prompt: Real time clock
> │ Defined at drivers/net/stmmac/Kconfig:50
> │ Depends on: <choice> && RTC_CLASS
> │ Location:
> │ -> Network device support (NETDEVICES [=y])
> │ -> Ethernet (1000 Mbit) (NETDEV_1000 [=n])
> │ -> STMicroelectronics 10/100/1000 Ethernet driver (STMMAC_ETH [=n])
> │ -> STMMAC Timer optimisation (STMMAC_TIMER [=n])
> │ -> Select Timer device (<choice> [=n])

Ouch. That has to be the strangest place one could *possibly* put an RTC driver. ;)

Giuseppe - is that RTC driver *really* an integral part of the chipset and
won't work without the Ethernet parts, or should the driver code for the RTC
live elsewhere in the tree?


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2011-05-30 04:17:20

by Peppe CAVALLARO

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Subject: Re: 2 small kernel config issues related to UML + RTC

Hi Valdis

On 5/29/2011 7:17 PM, [email protected] wrote:
> On Sun, 29 May 2011 11:22:01 +0200, Toralf F?rster said:
>> │ Symbol: STMMAC_RTC_TIMER [=n]
>> │ Type : boolean
>> │ Prompt: Real time clock
>> │ Defined at drivers/net/stmmac/Kconfig:50
>> │ Depends on: <choice> && RTC_CLASS
>> │ Location:
>> │ -> Network device support (NETDEVICES [=y])
>> │ -> Ethernet (1000 Mbit) (NETDEV_1000 [=n])
>> │ -> STMicroelectronics 10/100/1000 Ethernet driver (STMMAC_ETH [=n])
>> │ -> STMMAC Timer optimisation (STMMAC_TIMER [=n])
>> │ -> Select Timer device (<choice> [=n])
>
> Ouch. That has to be the strangest place one could *possibly* put an RTC driver. ;)
>
> Giuseppe - is that RTC driver *really* an integral part of the chipset and
> won't work without the Ethernet parts, or should the driver code for the RTC
> live elsewhere in the tree?

No the external RTC (or the SH-4 TMU) HW can be used by the driver to
handle the rx/tx process mitigating the DMA interrupts. This is not the
best approach but it actually helped many people to space the CPU
especially on old chips w/o dedicate timer.

It's likely I will remove all this code as soon as I work on a chip with
the embedded watchdog.

Regards
Giuseppe