From: Jon Hunter <jonathanh@nvidia.com>
To: "Dmitry Osipenko" <digetx@gmail.com>,
"Laxman Dewangan" <ldewangan@nvidia.com>,
"Vinod Koul" <vkoul@kernel.org>,
"Dan Williams" <dan.j.williams@intel.com>,
"Thierry Reding" <thierry.reding@gmail.com>,
"Michał Mirosław" <mirq-linux@rere.qmqm.pl>
Cc: <dmaengine@vger.kernel.org>, <linux-tegra@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v4 11/14] dmaengine: tegra-apb: Clean up suspend-resume
Date: Tue, 28 Jan 2020 14:10:24 +0000 [thread overview]
Message-ID: <831d5e28-72df-3175-bfb6-b33985d93a52@nvidia.com> (raw)
In-Reply-To: <7e0d2cfa-5570-93e6-e3dc-7d3f6902a528@gmail.com>
On 21/01/2020 21:23, Dmitry Osipenko wrote:
> 12.01.2020 20:30, Dmitry Osipenko пишет:
>> It is enough to check whether hardware is busy on suspend and to reset
>> it across of suspend-resume because channel's configuration is fully
>> re-programmed on each DMA transaction anyways and because save-restore
>> of an active channel won't end up well without pausing transfer prior to
>> saving of the state (note that all channels shall be idling at the time of
>> suspend, so save-restore is not needed at all).
>>
>> Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
>> ---
>> drivers/dma/tegra20-apb-dma.c | 131 +++++++++++++++++-----------------
>> 1 file changed, 67 insertions(+), 64 deletions(-)
>>
>> diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
>> index b9d8e57eaf54..398a0e1d6506 100644
>> --- a/drivers/dma/tegra20-apb-dma.c
>> +++ b/drivers/dma/tegra20-apb-dma.c
>> @@ -1392,6 +1392,36 @@ static const struct tegra_dma_chip_data tegra148_dma_chip_data = {
>> .support_separate_wcount_reg = true,
>> };
>>
>> +static int tegra_dma_init_hw(struct tegra_dma *tdma)
>> +{
>> + int err;
>> +
>> + err = reset_control_assert(tdma->rst);
>> + if (err) {
>> + dev_err(tdma->dev, "failed to assert reset: %d\n", err);
>> + return err;
>> + }
>> +
>> + err = clk_enable(tdma->dma_clk);
>> + if (err) {
>> + dev_err(tdma->dev, "failed to enable clk: %d\n", err);
>> + return err;
>> + }
>> +
>> + /* reset DMA controller */
>> + udelay(2);
>> + reset_control_deassert(tdma->rst);
>> +
>> + /* enable global DMA registers */
>> + tdma_write(tdma, TEGRA_APBDMA_GENERAL, TEGRA_APBDMA_GENERAL_ENABLE);
>> + tdma_write(tdma, TEGRA_APBDMA_CONTROL, 0);
>> + tdma_write(tdma, TEGRA_APBDMA_IRQ_MASK_SET, 0xFFFFFFFF);
>> +
>> + clk_disable(tdma->dma_clk);
>> +
>> + return 0;
>> +}
>> +
>> static int tegra_dma_probe(struct platform_device *pdev)
>> {
>> const struct tegra_dma_chip_data *cdata;
>> @@ -1433,30 +1463,18 @@ static int tegra_dma_probe(struct platform_device *pdev)
>> if (ret)
>> return ret;
>>
>> + ret = tegra_dma_init_hw(tdma);
>> + if (ret)
>> + goto err_clk_unprepare;
>> +
>> pm_runtime_irq_safe(&pdev->dev);
>> pm_runtime_enable(&pdev->dev);
>> if (!pm_runtime_enabled(&pdev->dev)) {
>> ret = tegra_dma_runtime_resume(&pdev->dev);
>> if (ret)
>> goto err_clk_unprepare;
>
> Jon, but isn't the RPM mandatory for all Tegra SoCs now and thus
> guaranteed to be enabled? Maybe we should start to remove handling the
> case of unavailable RPM from all Tegra drivers?
Yes that's true, even ARCH_TEGRA selects PM now
Cheers
Jon
--
nvpublic
next prev parent reply other threads:[~2020-01-28 14:44 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-12 17:29 [PATCH v4 00/14] NVIDIA Tegra APB DMA driver fixes and improvements Dmitry Osipenko
2020-01-12 17:29 ` [PATCH v4 01/14] dmaengine: tegra-apb: Fix use-after-free Dmitry Osipenko
2020-01-14 15:09 ` Jon Hunter
2020-01-14 20:33 ` Dmitry Osipenko
2020-01-15 9:00 ` Jon Hunter
2020-01-16 20:10 ` Dmitry Osipenko
2020-01-28 14:02 ` Jon Hunter
2020-01-28 14:51 ` Dmitry Osipenko
2020-01-29 0:12 ` Dmitry Osipenko
2020-01-29 10:42 ` Jon Hunter
2020-01-12 17:29 ` [PATCH v4 02/14] dmaengine: tegra-apb: Implement synchronization callback Dmitry Osipenko
2020-01-14 15:15 ` Jon Hunter
2020-01-14 21:02 ` Dmitry Osipenko
2020-01-15 9:18 ` Jon Hunter
2020-01-15 10:25 ` Jon Hunter
2020-01-12 17:29 ` [PATCH v4 03/14] dmaengine: tegra-apb: Prevent race conditions on channel's freeing Dmitry Osipenko
2020-01-14 15:16 ` Jon Hunter
2020-01-12 17:29 ` [PATCH v4 04/14] dmaengine: tegra-apb: Clean up tasklet releasing Dmitry Osipenko
2020-01-14 15:36 ` Jon Hunter
2020-01-12 17:29 ` [PATCH v4 05/14] dmaengine: tegra-apb: Prevent race conditions of tasklet vs free list Dmitry Osipenko
2020-01-14 15:43 ` Jon Hunter
2020-01-12 17:29 ` [PATCH v4 06/14] dmaengine: tegra-apb: Use devm_platform_ioremap_resource Dmitry Osipenko
2020-01-14 15:44 ` Jon Hunter
2020-01-12 17:29 ` [PATCH v4 07/14] dmaengine: tegra-apb: Use devm_request_irq Dmitry Osipenko
2020-01-14 15:44 ` Jon Hunter
2020-01-12 17:30 ` [PATCH v4 08/14] dmaengine: tegra-apb: Fix coding style problems Dmitry Osipenko
2020-01-15 9:49 ` Jon Hunter
2020-01-16 17:37 ` Dmitry Osipenko
2020-01-28 14:05 ` Jon Hunter
2020-01-28 15:01 ` Dmitry Osipenko
2020-01-12 17:30 ` [PATCH v4 09/14] dmaengine: tegra-apb: Clean up runtime PM teardown Dmitry Osipenko
2020-01-15 9:57 ` Jon Hunter
2020-01-16 17:18 ` Dmitry Osipenko
2020-01-12 17:30 ` [PATCH v4 10/14] dmaengine: tegra-apb: Keep clock enabled only during of DMA transfer Dmitry Osipenko
2020-01-15 10:08 ` Jon Hunter
2020-01-16 17:01 ` Dmitry Osipenko
2020-01-12 17:30 ` [PATCH v4 11/14] dmaengine: tegra-apb: Clean up suspend-resume Dmitry Osipenko
2020-01-21 21:23 ` Dmitry Osipenko
2020-01-28 14:10 ` Jon Hunter [this message]
2020-01-28 14:53 ` Dmitry Osipenko
2020-01-12 17:30 ` [PATCH v4 12/14] dmaengine: tegra-apb: Add missing of_dma_controller_free Dmitry Osipenko
2020-01-15 10:10 ` Jon Hunter
2020-01-12 17:30 ` [PATCH v4 13/14] dmaengine: tegra-apb: Allow to compile as a loadable kernel module Dmitry Osipenko
2020-01-15 10:10 ` Jon Hunter
2020-01-12 17:30 ` [PATCH v4 14/14] dmaengine: tegra-apb: Remove MODULE_ALIAS Dmitry Osipenko
2020-01-15 10:11 ` Jon Hunter
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