From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753670AbaIHIQG (ORCPT ); Mon, 8 Sep 2014 04:16:06 -0400 Received: from mailout3.w1.samsung.com ([210.118.77.13]:27075 "EHLO mailout3.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753492AbaIHIQA (ORCPT ); Mon, 8 Sep 2014 04:16:00 -0400 X-AuditID: cbfec7f5-b7f776d000003e54-aa-540d65bd2bd7 Message-id: <1410164155.4300.8.camel@AMDC1943> Subject: Re: [RFC PATCH] dma: pl330: add Power Management support From: Krzysztof Kozlowski To: Michal Simek Cc: Dan Williams , Vinod Koul , Lars-Peter Clausen , Dan Carpenter , dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org, Kyungmin Park , Marek Szyprowski , Bartlomiej Zolnierkiewicz Date: Mon, 08 Sep 2014 10:15:55 +0200 In-reply-to: <8b73ba80-c055-42c3-a784-96e120482319@BN1BFFO11FD058.protection.gbl> References: <1409929562-29583-1-git-send-email-k.kozlowski@samsung.com> <8b73ba80-c055-42c3-a784-96e120482319@BN1BFFO11FD058.protection.gbl> Content-type: text/plain; charset=UTF-8 X-Mailer: Evolution 3.10.4-0ubuntu2 MIME-version: 1.0 Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrELMWRmVeSWpSXmKPExsVy+t/xy7p7U3lDDN61GltsnLGe1eL1v+ks FtOnXmC0WD31L6vF2aY37BZLJs9ntbi8aw6bxdojd9kt3r2MsHjZt5/Fgctj8Z6XTB5L3hxi 9fj49BaLR9+WVYwenzfJeez9/JslgC2KyyYlNSezLLVI3y6BK2PasS0sBY0WFU1XpjI2ME7W 6WLk5JAQMJGY9egsE4QtJnHh3nq2LkYuDiGBpYwSC1o2sEA4nxklPh3qZwap4hXQk+ic+BvM FhZwlGhdOxGsm03AWGLz8iVsILaIgJbEp6brTCDNzALvmSS6+nvAGlgEVCX6bu4AK+IUCJbY sfM4E8SGPkaJ5fv2gyWYBdQlJs1bBNTAAXSTskRjvxvEYkGJH5PvsUCUyEtsXvOWeQKjwCwk HbOQlM1CUraAkXkVo2hqaXJBcVJ6rpFecWJucWleul5yfu4mRkg8fN3BuPSY1SFGAQ5GJR7e hKs8IUKsiWXFlbmHGCU4mJVEeBnCeEOEeFMSK6tSi/Lji0pzUosPMTJxcEo1MO4K+DtpluVP A837uxoZ/J6JCfB9i1kvP/FV9vSJggv/v8ndt8EyTXFP8hbthU9znvEllrEuv/DJRJJPo/Nf QRPXB+9Qhq7GT/89XR9m34o6uil6qX3tx8JPttP6fy86fGbRlNyI3W8kTR3W+VnkRFtPrJ/X OLFm/uuZU9LWCz4xaW4/t2/W30IlluKMREMt5qLiRABKpkBMZQIAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On pon, 2014-09-08 at 10:06 +0200, Michal Simek wrote: > On 09/05/2014 05:06 PM, Krzysztof Kozlowski wrote: > > This patch adds both normal PM suspend/resume support and runtime PM > > support to pl330 DMA engine driver. > > > > The runtime power management for pl330 DMA driver allows gating of AMBA > > clock (PDMA) in FSYS clock domain, when the device is not processing any > > requests. This is necessary to enter W-AFTR low power mode on Exynos3250. > > > > The patch is based on previous work of Bartlomiej Zolnierkiewicz > > . > > > > Signed-off-by: Krzysztof Kozlowski > > --- > > drivers/dma/pl330.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++--- > > 1 file changed, 74 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/dma/pl330.c b/drivers/dma/pl330.c > > index 66e89f04504c..bdc6ff8ee2bf 100644 > > --- a/drivers/dma/pl330.c > > +++ b/drivers/dma/pl330.c > > @@ -27,6 +27,7 @@ > > #include > > #include > > #include > > +#include > > > > #include "dmaengine.h" > > #define PL330_MAX_CHAN 8 > > @@ -1966,6 +1967,7 @@ static void pl330_tasklet(unsigned long data) > > struct dma_pl330_chan *pch = (struct dma_pl330_chan *)data; > > struct dma_pl330_desc *desc, *_dt; > > unsigned long flags; > > + bool power_down = false; > > > > spin_lock_irqsave(&pch->lock, flags); > > > > @@ -1980,10 +1982,17 @@ static void pl330_tasklet(unsigned long data) > > /* Try to submit a req imm. next to the last completed cookie */ > > fill_queue(pch); > > > > - /* Make sure the PL330 Channel thread is active */ > > - spin_lock(&pch->thread->dmac->lock); > > - _start(pch->thread); > > - spin_unlock(&pch->thread->dmac->lock); > > + if (list_empty(&pch->work_list)) { > > + spin_lock(&pch->thread->dmac->lock); > > + _stop(pch->thread); > > + spin_unlock(&pch->thread->dmac->lock); > > + power_down = true; > > + } else { > > + /* Make sure the PL330 Channel thread is active */ > > + spin_lock(&pch->thread->dmac->lock); > > + _start(pch->thread); > > + spin_unlock(&pch->thread->dmac->lock); > > + } > > > > while (!list_empty(&pch->completed_list)) { > > dma_async_tx_callback callback; > > @@ -1998,6 +2007,12 @@ static void pl330_tasklet(unsigned long data) > > if (pch->cyclic) { > > desc->status = PREP; > > list_move_tail(&desc->node, &pch->work_list); > > + if (power_down) { > > + spin_lock(&pch->thread->dmac->lock); > > + _start(pch->thread); > > + spin_unlock(&pch->thread->dmac->lock); > > + power_down = false; > > + } > > } else { > > desc->status = FREE; > > list_move_tail(&desc->node, &pch->dmac->desc_pool); > > @@ -2012,6 +2027,10 @@ static void pl330_tasklet(unsigned long data) > > } > > } > > spin_unlock_irqrestore(&pch->lock, flags); > > + > > + /* If work list empty, power down */ > > + if (power_down) > > + pm_runtime_put(pch->dmac->ddma.dev); > > } > > > > bool pl330_filter(struct dma_chan *chan, void *param) > > @@ -2077,10 +2096,12 @@ static int pl330_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned > > unsigned long flags; > > struct pl330_dmac *pl330 = pch->dmac; > > struct dma_slave_config *slave_config; > > + bool power_down = false; > > LIST_HEAD(list); > > > > switch (cmd) { > > case DMA_TERMINATE_ALL: > > + pm_runtime_get_sync(pl330->ddma.dev); > > spin_lock_irqsave(&pch->lock, flags); > > > > spin_lock(&pl330->lock); > > @@ -2107,10 +2128,18 @@ static int pl330_control(struct dma_chan *chan, enum dma_ctrl_cmd cmd, unsigned > > dma_cookie_complete(&desc->txd); > > } > > > > + if (!list_empty(&pch->work_list)) > > + power_down = true; > > + > > list_splice_tail_init(&pch->submitted_list, &pl330->desc_pool); > > list_splice_tail_init(&pch->work_list, &pl330->desc_pool); > > list_splice_tail_init(&pch->completed_list, &pl330->desc_pool); > > spin_unlock_irqrestore(&pch->lock, flags); > > + pm_runtime_put(pl330->ddma.dev); > > + > > + /* If work list empty, power down */ > > + if (power_down) > > + pm_runtime_put(pl330->ddma.dev); > > break; > > case DMA_SLAVE_CONFIG: > > slave_config = (struct dma_slave_config *)arg; > > @@ -2146,6 +2175,7 @@ static void pl330_free_chan_resources(struct dma_chan *chan) > > > > tasklet_kill(&pch->task); > > > > + pm_runtime_get_sync(pch->dmac->ddma.dev); > > spin_lock_irqsave(&pch->lock, flags); > > > > pl330_release_channel(pch->thread); > > @@ -2155,6 +2185,7 @@ static void pl330_free_chan_resources(struct dma_chan *chan) > > list_splice_tail_init(&pch->work_list, &pch->dmac->desc_pool); > > > > spin_unlock_irqrestore(&pch->lock, flags); > > + pm_runtime_put(pch->dmac->ddma.dev); > > } > > > > static enum dma_status > > @@ -2168,11 +2199,23 @@ static void pl330_issue_pending(struct dma_chan *chan) > > { > > struct dma_pl330_chan *pch = to_pchan(chan); > > unsigned long flags; > > + bool power_up; > > > > spin_lock_irqsave(&pch->lock, flags); > > + power_up = list_empty(&pch->work_list); > > list_splice_tail_init(&pch->submitted_list, &pch->work_list); > > spin_unlock_irqrestore(&pch->lock, flags); > > > > + if (power_up) { > > + /* > > + * Warn on nothing pending. This may break our pm_runtime > > + * usage counter as it is updated on work_list emptiness > > + * status. > > + */ > > + WARN_ON(list_empty(&pch->work_list)); > > + pm_runtime_get_sync(pch->dmac->ddma.dev); > > + } > > + > > pl330_tasklet((unsigned long)pch); > > } > > > > @@ -2205,6 +2248,7 @@ static dma_cookie_t pl330_tx_submit(struct dma_async_tx_descriptor *tx) > > > > cookie = dma_cookie_assign(&last->txd); > > list_add_tail(&last->node, &pch->submitted_list); > > + > > unrelated change. Right. > > > spin_unlock_irqrestore(&pch->lock, flags); > > > > return cookie; > > @@ -2593,6 +2637,28 @@ static int pl330_dma_device_slave_caps(struct dma_chan *dchan, > > return 0; > > } > > > > +#ifdef CONFIG_PM_SLEEP > > remove this line > > > +static int pl330_suspend(struct device *dev) > > __maybe_unused here > > > +{ > > + struct amba_device *pcdev = to_amba_device(dev); > > + > > + if (!pm_runtime_suspended(dev)) > > + amba_pclk_disable(pcdev); > > + return 0; > > +} > > + > > +static int pl330_resume(struct device *dev) > > __maybe_unused here > > > +{ > > + struct amba_device *pcdev = to_amba_device(dev); > > + > > + if (!pm_runtime_suspended(dev)) > > + return amba_pclk_enable(pcdev); > > + return 0; > > +} > > +#endif > > remove this line > > > + > > +static SIMPLE_DEV_PM_OPS(pl330_pm, pl330_suspend, pl330_resume); > > Everything is handle inside this macro and your functions are not calling > anything what it is not defined for both cases. Thank you for feedback. I'll fix this in next version. Best regards, Krzysztof > > Thanks, > Michal >