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From: Greg KH <greg@kroah.com>
To: Tomek The Messenger <tomekthemessenger@gmail.com>
Cc: kernelnewbies@kernelnewbies.org
Subject: Re: how to perform i2c transaction with disabled irq?
Date: Thu, 30 Apr 2020 13:20:47 +0200	[thread overview]
Message-ID: <20200430112047.GA2945793@kroah.com> (raw)
In-Reply-To: <CAA4NGysEjWQQG82uR83H=D_6tydNiwquu=peQhPq5PSRmaHevQ@mail.gmail.com>

On Thu, Apr 30, 2020 at 01:11:06PM +0200, Tomek The Messenger wrote:
> Hi
> If I don't have disabled irqs I can use API i2c_smbus_write_byte in order
> to perform i2c transaction.
> But how to make i2c transaction if I have disabled irq? Is any built-in
> function which lets such operation, where there is some polling implemented?
> The background is that I do i2c transaction in restart handler (some i2c
> transaction to hot swap controller) in order to reset board.  And linux
> before entering restart handler list disable interrupts. There is a
> function to enable back interrupts but in company in which I am working
> engineers reviewed it and said "it is not allowed, restart must be
> performed when interrupts are disabled".

Ask the engineers how you are supposed to use an interrupt driven device
with interrupts disabled.

good luck!

greg k-h

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  reply	other threads:[~2020-04-30 11:21 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-04-30 11:11 how to perform i2c transaction with disabled irq? Tomek The Messenger
2020-04-30 11:20 ` Greg KH [this message]
2020-04-30 14:13   ` Tomek The Messenger

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