From: Lukas Wunner <lukas@wunner.de>
To: Mark Brown <broonie@kernel.org>
Cc: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>,
Martin Sperl <kernel@martin.sperl.org>,
linux-spi@vger.kernel.org, linux-rpi-kernel@lists.infradead.org,
Linus Walleij <linus.walleij@linaro.org>
Subject: Re: [PATCH 1/5] spi: Fix controller unregister order
Date: Fri, 15 May 2020 18:31:47 +0200 [thread overview]
Message-ID: <20200515163147.3u4xjqdxci2neup7@wunner.de> (raw)
In-Reply-To: <20200515162725.GG5066@sirena.org.uk>
On Fri, May 15, 2020 at 05:27:25PM +0100, Mark Brown wrote:
> On Fri, May 15, 2020 at 05:58:01PM +0200, Lukas Wunner wrote:
> > However since commit ffbbdd21329f ("spi: create a message queueing
> > infrastructure"), spi_destroy_queue() is executed before unbinding the
> > slaves. It sets ctlr->running = false, thereby preventing SPI bus
> > access and causing unbinding of slave devices to fail.
>
> Devices should basically never fail an unbind operation - if something
> went seriously wrong there's basically nothing that can be done in terms
> of error handling and keeping the device around isn't going to help.
I guess the word "fail" in the commit message invites misinterpretations.
The driver does unbind from the slave device, but the physical device is
not left in a proper state. E.g. interrupts may still be generated by
the device because writing a register to disable them failed.
Thanks,
Lukas
next prev parent reply other threads:[~2020-05-15 16:41 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-15 15:58 [PATCH 0/5] Raspberry Pi SPI unbind fixes Lukas Wunner
2020-05-15 15:58 ` [PATCH 1/5] spi: Fix controller unregister order Lukas Wunner
2020-05-15 16:27 ` Mark Brown
2020-05-15 16:31 ` Lukas Wunner [this message]
2020-05-15 21:37 ` Andy Shevchenko
2020-05-16 6:45 ` Lukas Wunner
2020-05-16 9:45 ` Andy Shevchenko
2020-05-15 15:58 ` [PATCH 2/5] spi: bcm2835: " Lukas Wunner
2020-05-15 16:29 ` Mark Brown
2020-05-15 16:44 ` Lukas Wunner
2020-05-15 21:33 ` Andy Shevchenko
2020-05-16 6:56 ` Lukas Wunner
2020-05-16 9:40 ` Andy Shevchenko
2020-05-15 15:58 ` [PATCH 3/5] spi: bcm2835aux: " Lukas Wunner
2020-05-15 15:58 ` [PATCH 4/5] spi: bcm2835: Tear down DMA before turning off SPI controller Lukas Wunner
2020-05-15 15:58 ` [PATCH 5/5] spi: Document devm_spi_register_controller() gotcha Lukas Wunner
2020-05-15 16:30 ` Mark Brown
2020-05-20 17:17 ` [PATCH 0/5] Raspberry Pi SPI unbind fixes Mark Brown
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