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Date:   Thu, 3 Aug 2023 14:40:05 +0300
From:   Andy Shevchenko <andriy.shevchenko@linux.intel.com>
To:     Conor Dooley <conor@kernel.org>
Cc:     Jisheng Zhang <jszhang@kernel.org>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Ilpo =?iso-8859-1?Q?J=E4rvinen?= <ilpo.jarvinen@linux.intel.com>,
        Jiri Slaby <jirislaby@kernel.org>,
        linux-serial@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/2] dt-bindings: serial: snps-dw-apb-uart: make
 interrupt optional
Message-ID: <ZMuSFYQ4YyIKnI0k@smile.fi.intel.com>
References: <20230802150545.3742-1-jszhang@kernel.org>
 <20230802150545.3742-2-jszhang@kernel.org>
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 <ZMrRWP5mK+nksn4M@smile.fi.intel.com>
 <20230802-risk-getting-e6005e86be81@spud>
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On Wed, Aug 02, 2023 at 11:53:59PM +0100, Conor Dooley wrote:
> On Thu, Aug 03, 2023 at 12:57:44AM +0300, Andy Shevchenko wrote:
> > On Wed, Aug 02, 2023 at 04:43:48PM +0100, Conor Dooley wrote:
> > > On Wed, Aug 02, 2023 at 11:05:44PM +0800, Jisheng Zhang wrote:
> > > > The driver fall back to poll style when there's no irq. "poll" still
> > > > looks better than no support.
> > > 
> > > What is the user for this where the interrupt is not actually wired up
> > > in the hardware?
> > 
> > FYI: kernel console doesn't use interrupts, so for example it might be
> > the debug port. Note, I have no idea of the Zhang's case, just my assumption.
> 
> I'm less interested in what the software is doing, it's what the device 
> that has not connected the interrupt is that I am curious about.

As I said. The hw may be purely for debugging purposes (and yes, I have heard
about such a hardware).

-- 
With Best Regards,
Andy Shevchenko