From: Sowjanya Komatineni <skomatineni@nvidia.com>
To: Dmitry Osipenko <digetx@gmail.com>,
"thierry.reding@gmail.com" <thierry.reding@gmail.com>,
Jonathan Hunter <jonathanh@nvidia.com>,
Mantravadi Karthik <mkarthik@nvidia.com>,
Shardar Mohammed <smohammed@nvidia.com>,
Timo Alho <talho@nvidia.com>
Cc: "linux-tegra@vger.kernel.org" <linux-tegra@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-i2c@vger.kernel.org" <linux-i2c@vger.kernel.org>
Subject: RE: [PATCH V9 3/5] i2c: tegra: Add DMA support
Date: Sat, 2 Feb 2019 18:43:57 +0000 [thread overview]
Message-ID: <BYAPR12MB339885398C3B0218D452B6CAC2930@BYAPR12MB3398.namprd12.prod.outlook.com> (raw)
In-Reply-To: <f667ab55-c7c7-4ac1-100a-7f7ade87708d@gmail.com>
> >>>> +static int tegra_i2c_init_dma(struct tegra_i2c_dev *i2c_dev) {
> >>>> + struct dma_chan *dma_chan;
> >>>> + u32 *dma_buf;
> >>>> + dma_addr_t dma_phys;
> >>>> + int err = 0;
> >>>> +
> >>>> + if (!IS_ENABLED(CONFIG_TEGRA20_APB_DMA))
> >>>> + return -ENODEV;
> >>>
> >>> Driver shall not fail to probe if DMA driver is disabled, but to continue with the PIO-only mode available.
> >>>
> >>> Should be:
> >>>
> >>> if (!IS_ENABLED(CONFIG_TEGRA20_APB_DMA))
> >>> return 0;
> >>>
> >> Except EPROBE_DEFER, anything else returned from tegra_i2c_init_dma
> >> (ENODEV/ENOMEM) is ignored in i2c_probe DMA mode decision is based on xfer size and availability of dma channel or can be changed based on valid dma buf to shorten the line.
> >>
> >
> > Ah, sorry. I missed that, seems good then.
> >
>
> BTW, it may be worthwhile to move out the error code handling into tegra_i2c_init_dma() for clarity. It also won't hurt to not ignore errors other than -ENODEV.
Either ways are same. To be more readable/clear on error types for diff cases and errors that we are ignoring, I am explicitly keeping error codecs (EPROBE_DEFER/ENODEV/ENOMEM) same way.
Also in probe for readability checking with EPROBE_DEFER which explicitly indicating we keep deferring i2c probe rather than simple return.
next prev parent reply other threads:[~2019-02-02 18:44 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-01 17:07 [PATCH V9 1/5] i2c: tegra: sort all the include headers alphabetically Sowjanya Komatineni
2019-02-01 17:07 ` [PATCH V9 2/5] i2c: tegra: add bus clear master support Sowjanya Komatineni
2019-02-01 19:06 ` Dmitry Osipenko
2019-02-01 17:07 ` [PATCH V9 3/5] i2c: tegra: Add DMA support Sowjanya Komatineni
2019-02-01 18:57 ` Dmitry Osipenko
2019-02-01 19:20 ` Sowjanya Komatineni
2019-02-01 19:22 ` Dmitry Osipenko
2019-02-02 14:13 ` Dmitry Osipenko
2019-02-02 18:43 ` Sowjanya Komatineni [this message]
2019-02-03 16:42 ` Dmitry Osipenko
2019-02-01 20:21 ` Sowjanya Komatineni
2019-02-01 20:30 ` Dmitry Osipenko
2019-02-01 21:36 ` Sowjanya Komatineni
2019-02-01 21:45 ` Dmitry Osipenko
2019-02-02 14:01 ` Dmitry Osipenko
2019-02-02 18:32 ` Sowjanya Komatineni
2019-02-03 16:48 ` Dmitry Osipenko
2019-02-04 8:18 ` Thierry Reding
2019-02-03 14:19 ` Dmitry Osipenko
2019-02-03 14:47 ` Dmitry Osipenko
2019-02-03 15:27 ` Dmitry Osipenko
2019-02-04 12:57 ` Dmitry Osipenko
2019-02-05 1:37 ` Sowjanya Komatineni
2019-02-05 6:20 ` Dmitry Osipenko
2019-02-04 8:04 ` Thierry Reding
2019-02-01 17:07 ` [PATCH V9 4/5] i2c: tegra: update transfer timeout Sowjanya Komatineni
2019-02-01 19:16 ` Dmitry Osipenko
2019-02-01 19:37 ` Sowjanya Komatineni
2019-02-01 19:41 ` Dmitry Osipenko
2019-02-04 7:54 ` Thierry Reding
2019-02-01 17:07 ` [PATCH V9 5/5] i2c: tegra: add i2c interface timing support Sowjanya Komatineni
2019-02-01 19:05 ` [PATCH V9 1/5] i2c: tegra: sort all the include headers alphabetically Dmitry Osipenko
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