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From: Kalle Valo <kvalo@kernel.org>
To: <Ajay.Kathat@microchip.com>
Cc: <davidm@egauge.net>,  <linux-wireless@vger.kernel.org>
Subject: Re: RFQ: wifi: wilc1000: make wilc1000-spi bus-probe useful
References: <90fb762e5840f9d5a6ae46f81692fb947a7796a4.camel@egauge.net>
	<1776feff-0886-4db8-896c-c542d3e626b0@microchip.com>
Date: Tue, 23 Jan 2024 08:31:19 +0200
In-Reply-To: <1776feff-0886-4db8-896c-c542d3e626b0@microchip.com> (Ajay
	Kathat's message of "Mon, 22 Jan 2024 16:57:10 +0000")
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<Ajay.Kathat@microchip.com> writes:

> On 1/19/24 14:51, David Mosberger-Tang wrote:
>> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>> 
>> The current version of the wilc1000 driver has a probe function that simply
>> assumes the chip is present. It is only later, in wilc_spi_init(), that the
>> driver verifies that it can actually communicate with the chip. The result of
>> this is that the net device (typically wlan0) is created and remains in place as
>> long as the wilc1000-spi driver is loaded, even if the WILC1000 chip is not
>> present or not working.
>> 
>> Is there any reason not to detect the chip's present in wilc_bus_probe()? The
>> patch below (relative to 5.15.147) works for me, but perhaps I'm missing
>> something? Would it make sense to merge something along these lines into
>> mainline?
>> 
>
> I think it is the WILC driver design that the firmware/chip operations
> are executed only when the netdev interface(wlan0) is up.

Yeah, that's good design. I think that wlan0 is down wireless drivers
should turn off the hardware to reduce power consumption as much as
possible. Many drivers do start the firmware during probe() to query the
capabilities and then turn it off immediately.

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