Re: [PATCH 06/10] watchdog: ebc-c384_wdt: Utilize the ISA bus driver

From: William Breathitt Gray
Date: Fri Apr 08 2016 - 08:04:53 EST


On Thu, Apr 07, 2016 at 05:35:35PM -0700, Guenter Roeck wrote:
>I am a bit concerend that the newly introduced ISA_BUS is not automatically
>enabled. Effectively this means that all drivers depending on it will
>be disabled until someone enables ISA_BUS in the distribution.
>
>Is this a concern for anyone but me ?
>
>Anyway, since you are the driver maintainer, I assume that you are ok
>with it, so
>
>Acked-by: Guenter Roeck <linux@xxxxxxxxxxxx>
>
>Side note for Wim: ISA_BUS was introduced with commit b3c1be1b789c
>("base: isa: Remove X86_32 dependency") in -next.
>
>Guenter

Since the ISA bus lacks standardized probing functionality, and the
majority of ISA devices I've encountered expect the user to start
writing to the device's I/O port addresses from the get-go, I think
ISA_BUS should remain an explicit dependency rather than become selected
when a user chooses a driver. That is to say, it is more appropriate for
a user to explicitly enable ISA_BUS if their system has an ISA bus;
otherwise a user may enable a driver with the expectation of a device
probe, whereas the driver will simply start writing to I/O port
addresses unexpectedly.

William Breathitt Gray