Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Subject: Re: [PATCH v1 3/7] spi: qspi-tegra: Add support for Tegra210 QSPI
 controller
To:     Lukas Wunner <lukas@wunner.de>
CC:     <thierry.reding@gmail.com>, <jonathanh@nvidia.com>,
        <broonie@kernel.org>, <linux-spi@vger.kernel.org>,
        <linux-tegra@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <1606857168-5839-1-git-send-email-skomatineni@nvidia.com>
 <1606857168-5839-4-git-send-email-skomatineni@nvidia.com>
 <20201206181612.GA26286@wunner.de>
From:   Sowjanya Komatineni <skomatineni@nvidia.com>
Message-ID: <8ce3fa3a-88d7-e981-731a-9bce85047892@nvidia.com>
Date:   Mon, 7 Dec 2020 16:14:53 -0800
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101
 Thunderbird/68.10.0
MIME-Version: 1.0
In-Reply-To: <20201206181612.GA26286@wunner.de>
Content-Type: text/plain; charset="utf-8"; format=flowed
Content-Transfer-Encoding: 7bit
Content-Language: en-US
Precedence: bulk


On 12/6/20 10:16 AM, Lukas Wunner wrote:
> On Tue, Dec 01, 2020 at 01:12:44PM -0800, Sowjanya Komatineni wrote:
>> +	ret = devm_spi_register_master(&pdev->dev, master);
> [...]
>> +static int tegra_qspi_remove(struct platform_device *pdev)
>> +{
>> +	struct spi_master *master = platform_get_drvdata(pdev);
>> +	struct tegra_qspi_data	*tqspi = spi_master_get_devdata(master);
>> +
>> +	free_irq(tqspi->irq, tqspi);
>> +
>> +	tegra_qspi_deinit_dma_param(tqspi, false);
>> +	tegra_qspi_deinit_dma_param(tqspi, true);
>> +
>> +	pm_runtime_disable(&pdev->dev);
>> +	if (!pm_runtime_status_suspended(&pdev->dev))
>> +		tegra_qspi_runtime_suspend(&pdev->dev);
>> +
>> +	return 0;
>> +}
> With devm_spi_register_master(), the SPI controller is unregistered
> *after* tegra_qspi_remove().  SPI transactions may still be ongoing
> until the SPI controller is unregistered, yet you perform teardown
> steps (such as freeing the IRQ) while it is still registered.
>
> Bottom line is, you can't use devm_spi_register_master() in this case.
> You need to use spi_register_master() and explicitly call
> spi_unregister_master() in tegra_qspi_remove() *before* performing
> teardown steps.
>
> However, be sure to use the devm variant to *allocate* the SPI controller,
> i.e. use devm_spi_alloc_master() instead of spi_alloc_master().
>
> Thanks,
>
> Lukas

Thanks Lukas. I see devm_spi_alloc_master() in 5.4 but not from 5.5

Thanks

Sowjanya