[PATCH] watchdog: Add hardware dependency to BCM7038 driver

[PATCH] watchdog: Add hardware dependency to BCM7038 driver

[Jean Delvare]

The BCM7038 is a MIPS chip so do not present its driver on other
architectures, unless build-testing.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Cc: Justin Chen <justinpopo6@gmail.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Wim Van Sebroeck <wim@iguana.be>
---
 drivers/watchdog/Kconfig |    1 +
 1 file changed, 1 insertion(+)

--- linux-4.5-rc5.orig/drivers/watchdog/Kconfig	2016-02-21 13:44:07.845576963 +0100
+++ linux-4.5-rc5/drivers/watchdog/Kconfig	2016-02-22 12:07:20.865871451 +0100
@@ -1377,6 +1377,7 @@ config BCM7038_WDT
 	tristate "BCM7038 Watchdog"
 	select WATCHDOG_CORE
 	depends on HAS_IOMEM
+	depends on MIPS || COMPILE_TEST
 	help
 	 Watchdog driver for the built-in hardware in Broadcom 7038 SoCs.
 


-- 
Jean Delvare
SUSE L3 Support

Re: [PATCH] watchdog: Add hardware dependency to BCM7038 driver

[Guenter Roeck]

On 02/22/2016 03:11 AM, Jean Delvare wrote:
> The BCM7038 is a MIPS chip so do not present its driver on other
> architectures, unless build-testing.
>
> Signed-off-by: Jean Delvare <jdelvare@suse.de>
> Cc: Justin Chen <justinpopo6@gmail.com>
> Cc: Guenter Roeck <linux@roeck-us.net>
> Cc: Wim Van Sebroeck <wim@iguana.be>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>

Re: [PATCH] watchdog: Add hardware dependency to BCM7038 driver

[Justin Chen]

Hello Jean,

This driver is based off of a Broadcom watchdog block, it is not tied
to the MIPS core.
The watchdog driver is named BCM7038 because that was the first chip
that featured this watchdog block. Their are other chips that use this
driver that are not MIPS based.

Thanks,
Justin



On Mon, Feb 22, 2016 at 6:49 AM, Guenter Roeck <linux@roeck-us.net> wrote:
> On 02/22/2016 03:11 AM, Jean Delvare wrote:
>>
>> The BCM7038 is a MIPS chip so do not present its driver on other
>> architectures, unless build-testing.
>>
>> Signed-off-by: Jean Delvare <jdelvare@suse.de>
>> Cc: Justin Chen <justinpopo6@gmail.com>
>> Cc: Guenter Roeck <linux@roeck-us.net>
>> Cc: Wim Van Sebroeck <wim@iguana.be>
>
>
> Reviewed-by: Guenter Roeck <linux@roeck-us.net>
>

Re: [PATCH] watchdog: Add hardware dependency to BCM7038 driver

[Jean Delvare]

Hello Justin,

Le Monday 22 February 2016 à 09:58 -0800, Justin Chen a écrit :
> This driver is based off of a Broadcom watchdog block, it is not tied
> to the MIPS core.
> The watchdog driver is named BCM7038 because that was the first chip
> that featured this watchdog block. Their are other chips that use this
> driver that are not MIPS based.

The Kconfig help text doesn't say this at all. With the current wording
there is no reason why anyone would enable this option if not building a
kernel for the Broadcom BCM7038.

Which other systems reuse this watchdog block exactly? In the kernel
tree I can't see anyone instantiating this device.

-- 
Jean Delvare
SUSE L3 Support

Re: [PATCH] watchdog: Add hardware dependency to BCM7038 driver

[Justin Chen]

On Mon, Feb 22, 2016 at 10:43 AM, Jean Delvare <jdelvare@suse.de> wrote:
> Hello Justin,
>
> Le Monday 22 February 2016 à 09:58 -0800, Justin Chen a écrit :
>> This driver is based off of a Broadcom watchdog block, it is not tied
>> to the MIPS core.
>> The watchdog driver is named BCM7038 because that was the first chip
>> that featured this watchdog block. Their are other chips that use this
>> driver that are not MIPS based.
>
> The Kconfig help text doesn't say this at all. With the current wording
> there is no reason why anyone would enable this option if not building a
> kernel for the Broadcom BCM7038.
Sorry about that! I can submit a patch to fix this.
>
> Which other systems reuse this watchdog block exactly? In the kernel
> tree I can't see anyone instantiating this device.
BRCMSTB chips use this block as well as other BCM chips.

"This driver is for a watchdog block contained in all Broadcom Set-top
Box chips since BCM7038. BCM7038 was made public during the 2004 CES,
and since then, many chips use this watchdog block including some cable
modem chips."
>
> --
> Jean Delvare
> SUSE L3 Support
>

Re: [PATCH] watchdog: Add hardware dependency to BCM7038 driver

[Guenter Roeck]

On Mon, Feb 22, 2016 at 11:16:30AM -0800, Justin Chen wrote:
> On Mon, Feb 22, 2016 at 10:43 AM, Jean Delvare <jdelvare@suse.de> wrote:
> > Hello Justin,
> >
> > Le Monday 22 February 2016 à 09:58 -0800, Justin Chen a écrit :
> >> This driver is based off of a Broadcom watchdog block, it is not tied
> >> to the MIPS core.
> >> The watchdog driver is named BCM7038 because that was the first chip
> >> that featured this watchdog block. Their are other chips that use this
> >> driver that are not MIPS based.
> >
> > The Kconfig help text doesn't say this at all. With the current wording
> > there is no reason why anyone would enable this option if not building a
> > kernel for the Broadcom BCM7038.
> Sorry about that! I can submit a patch to fix this.
> >
> > Which other systems reuse this watchdog block exactly? In the kernel
> > tree I can't see anyone instantiating this device.
> BRCMSTB chips use this block as well as other BCM chips.
> 
> "This driver is for a watchdog block contained in all Broadcom Set-top
> Box chips since BCM7038. BCM7038 was made public during the 2004 CES,
> and since then, many chips use this watchdog block including some cable
> modem chips."

That is a bit vague. Can you be more specific ?

Also, while the driver may not be limited to MIPS, I am relatively sure
that it has some architecture limits. MIPS, ARM, and ARM64, maybe ?

Thanks,
Guenter

Re: [PATCH] watchdog: Add hardware dependency to BCM7038 driver

[Justin Chen]

On Mon, Feb 22, 2016 at 4:16 PM, Guenter Roeck <linux@roeck-us.net> wrote:
> On Mon, Feb 22, 2016 at 11:16:30AM -0800, Justin Chen wrote:
>> On Mon, Feb 22, 2016 at 10:43 AM, Jean Delvare <jdelvare@suse.de> wrote:
>> > Hello Justin,
>> >
>> > Le Monday 22 February 2016 à 09:58 -0800, Justin Chen a écrit :
>> >> This driver is based off of a Broadcom watchdog block, it is not tied
>> >> to the MIPS core.
>> >> The watchdog driver is named BCM7038 because that was the first chip
>> >> that featured this watchdog block. Their are other chips that use this
>> >> driver that are not MIPS based.
>> >
>> > The Kconfig help text doesn't say this at all. With the current wording
>> > there is no reason why anyone would enable this option if not building a
>> > kernel for the Broadcom BCM7038.
>> Sorry about that! I can submit a patch to fix this.
>> >
>> > Which other systems reuse this watchdog block exactly? In the kernel
>> > tree I can't see anyone instantiating this device.
>> BRCMSTB chips use this block as well as other BCM chips.
>>
>> "This driver is for a watchdog block contained in all Broadcom Set-top
>> Box chips since BCM7038. BCM7038 was made public during the 2004 CES,
>> and since then, many chips use this watchdog block including some cable
>> modem chips."
>
Hello Guenter,
> That is a bit vague. Can you be more specific ?
>
> Also, while the driver may not be limited to MIPS, I am relatively sure
> that it has some architecture limits. MIPS, ARM, and ARM64, maybe ?
Yes you are correct, this driver would be limited to Broadcom chips. I
would suggest "depends on ARCH_BRCMSTB || BMIPS_GENERIC ||
COMPILE_TEST"
>
> Thanks,
> Guenter

Thanks,
Justin

Re: [PATCH] watchdog: Add hardware dependency to BCM7038 driver

[Jean Delvare]

On Mon, 22 Feb 2016 16:27:52 -0800, Justin Chen wrote:
> On Mon, Feb 22, 2016 at 4:16 PM, Guenter Roeck <linux@roeck-us.net> wrote:
> > On Mon, Feb 22, 2016 at 11:16:30AM -0800, Justin Chen wrote:
> >> On Mon, Feb 22, 2016 at 10:43 AM, Jean Delvare <jdelvare@suse.de> wrote:
> >> > Hello Justin,
> >> >
> >> > Le Monday 22 February 2016 à 09:58 -0800, Justin Chen a écrit :
> >> >> This driver is based off of a Broadcom watchdog block, it is not tied
> >> >> to the MIPS core.
> >> >> The watchdog driver is named BCM7038 because that was the first chip
> >> >> that featured this watchdog block. Their are other chips that use this
> >> >> driver that are not MIPS based.
> >> >
> >> > The Kconfig help text doesn't say this at all. With the current wording
> >> > there is no reason why anyone would enable this option if not building a
> >> > kernel for the Broadcom BCM7038.
> >> Sorry about that! I can submit a patch to fix this.
> >> >
> >> > Which other systems reuse this watchdog block exactly? In the kernel
> >> > tree I can't see anyone instantiating this device.
> >> BRCMSTB chips use this block as well as other BCM chips.
> >>
> >> "This driver is for a watchdog block contained in all Broadcom Set-top
> >> Box chips since BCM7038. BCM7038 was made public during the 2004 CES,
> >> and since then, many chips use this watchdog block including some cable
> >> modem chips."
> >
> > That is a bit vague. Can you be more specific ?

Still a lot better than what the Kconfig has at the moment.

> > Also, while the driver may not be limited to MIPS, I am relatively sure
> > that it has some architecture limits. MIPS, ARM, and ARM64, maybe ?
> Yes you are correct, this driver would be limited to Broadcom chips. I
> would suggest "depends on ARCH_BRCMSTB || BMIPS_GENERIC ||
> COMPILE_TEST"

Thanks, I like it. I'll submit a v2 of the patch with this change and a
better description of the option.

-- 
Jean Delvare
SUSE L3 Support