From 97977f7576a89cb9436c000ae703c0d515e748ac Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Wed, 7 May 2014 10:56:24 +0300 Subject: dmaengine: dw: went back to plain {request,free}_irq() calls The commit dbde5c29 "dw_dmac: use devm_* functions to simplify code" turns probe function to use devm_* helpers and simultaneously brings a regression. We need to ensure irq is disabled, followed by ensuring that don't schedule any more tasklets and then its safe to use tasklet_kill(). The free_irq() will ensure that the irq is disabled and also wait till all scheduled interrupts are executed by invoking synchronize_irq(). So we need to only do tasklet_kill() after invoking free_irq(). Signed-off-by: Andy Shevchenko Cc: stable@vger.kernel.org # v3.11+ Signed-off-by: Vinod Koul --- drivers/dma/dw/core.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) (limited to 'drivers/dma/dw') diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c index cfdbb92aae1d..7a740769c2fa 100644 --- a/drivers/dma/dw/core.c +++ b/drivers/dma/dw/core.c @@ -1548,11 +1548,6 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata) /* Disable BLOCK interrupts as well */ channel_clear_bit(dw, MASK.BLOCK, dw->all_chan_mask); - err = devm_request_irq(chip->dev, chip->irq, dw_dma_interrupt, - IRQF_SHARED, "dw_dmac", dw); - if (err) - return err; - /* Create a pool of consistent memory blocks for hardware descriptors */ dw->desc_pool = dmam_pool_create("dw_dmac_desc_pool", chip->dev, sizeof(struct dw_desc), 4, 0); @@ -1563,6 +1558,11 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata) tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw); + err = request_irq(chip->irq, dw_dma_interrupt, IRQF_SHARED, + "dw_dmac", dw); + if (err) + return err; + INIT_LIST_HEAD(&dw->dma.channels); for (i = 0; i < nr_channels; i++) { struct dw_dma_chan *dwc = &dw->chan[i]; @@ -1667,6 +1667,7 @@ int dw_dma_remove(struct dw_dma_chip *chip) dw_dma_off(dw); dma_async_device_unregister(&dw->dma); + free_irq(chip->irq, dw); tasklet_kill(&dw->tasklet); list_for_each_entry_safe(dwc, _dwc, &dw->dma.channels, -- cgit v1.2.3-55-g7522 From d2f78e95e42a9130002c76f1a1f76e657a4b4004 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Thu, 8 May 2014 12:01:48 +0300 Subject: dmaengine: dw: enable clock before access hclk signal is a bus clock. So, it means we have to have it enabled during access to the DMA controller. This patch makes sure that we enable clock before access to the device, though it currently works on Intel hardware. Signed-off-by: Andy Shevchenko Signed-off-by: Vinod Koul --- drivers/dma/dw/core.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'drivers/dma/dw') diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c index 7a740769c2fa..009dc62f9437 100644 --- a/drivers/dma/dw/core.c +++ b/drivers/dma/dw/core.c @@ -1493,6 +1493,11 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata) dw->regs = chip->regs; chip->dw = dw; + dw->clk = devm_clk_get(chip->dev, "hclk"); + if (IS_ERR(dw->clk)) + return PTR_ERR(dw->clk); + clk_prepare_enable(dw->clk); + dw_params = dma_read_byaddr(chip->regs, DW_PARAMS); autocfg = dw_params >> DW_PARAMS_EN & 0x1; @@ -1520,11 +1525,6 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata) if (!dw->chan) return -ENOMEM; - dw->clk = devm_clk_get(chip->dev, "hclk"); - if (IS_ERR(dw->clk)) - return PTR_ERR(dw->clk); - clk_prepare_enable(dw->clk); - /* Get hardware configuration parameters */ if (autocfg) { max_blk_size = dma_readl(dw, MAX_BLK_SIZE); -- cgit v1.2.3-55-g7522 From 8be4f523b48087765defd18483c66b268b3286e5 Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Thu, 8 May 2014 12:01:49 +0300 Subject: dmaengine: dw: fix regression in dw_probe() function The commit dbde5c29 "dw_dmac: use devm_* functions to simplify code" turns probe function to use devm_* helpers and simultaneously brings a regression. We have to 1) call clk_disable_unprepare() on error path, and 2) check error code of clk_enable_prepare(). First part was done in the original code, second one is an update. Signed-off-by: Andy Shevchenko Signed-off-by: Vinod Koul --- drivers/dma/dw/core.c | 33 ++++++++++++++++++++++++--------- 1 file changed, 24 insertions(+), 9 deletions(-) (limited to 'drivers/dma/dw') diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c index 009dc62f9437..d539019fbe60 100644 --- a/drivers/dma/dw/core.c +++ b/drivers/dma/dw/core.c @@ -1496,7 +1496,9 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata) dw->clk = devm_clk_get(chip->dev, "hclk"); if (IS_ERR(dw->clk)) return PTR_ERR(dw->clk); - clk_prepare_enable(dw->clk); + err = clk_prepare_enable(dw->clk); + if (err) + return err; dw_params = dma_read_byaddr(chip->regs, DW_PARAMS); autocfg = dw_params >> DW_PARAMS_EN & 0x1; @@ -1505,15 +1507,19 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata) if (!pdata && autocfg) { pdata = devm_kzalloc(chip->dev, sizeof(*pdata), GFP_KERNEL); - if (!pdata) - return -ENOMEM; + if (!pdata) { + err = -ENOMEM; + goto err_pdata; + } /* Fill platform data with the default values */ pdata->is_private = true; pdata->chan_allocation_order = CHAN_ALLOCATION_ASCENDING; pdata->chan_priority = CHAN_PRIORITY_ASCENDING; - } else if (!pdata || pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS) - return -EINVAL; + } else if (!pdata || pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS) { + err = -EINVAL; + goto err_pdata; + } if (autocfg) nr_channels = (dw_params >> DW_PARAMS_NR_CHAN & 0x7) + 1; @@ -1522,8 +1528,10 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata) dw->chan = devm_kcalloc(chip->dev, nr_channels, sizeof(*dw->chan), GFP_KERNEL); - if (!dw->chan) - return -ENOMEM; + if (!dw->chan) { + err = -ENOMEM; + goto err_pdata; + } /* Get hardware configuration parameters */ if (autocfg) { @@ -1553,7 +1561,8 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata) sizeof(struct dw_desc), 4, 0); if (!dw->desc_pool) { dev_err(chip->dev, "No memory for descriptors dma pool\n"); - return -ENOMEM; + err = -ENOMEM; + goto err_pdata; } tasklet_init(&dw->tasklet, dw_dma_tasklet, (unsigned long)dw); @@ -1561,7 +1570,7 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata) err = request_irq(chip->irq, dw_dma_interrupt, IRQF_SHARED, "dw_dmac", dw); if (err) - return err; + goto err_pdata; INIT_LIST_HEAD(&dw->dma.channels); for (i = 0; i < nr_channels; i++) { @@ -1656,6 +1665,10 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata) dma_async_device_register(&dw->dma); return 0; + +err_pdata: + clk_disable_unprepare(dw->clk); + return err; } EXPORT_SYMBOL_GPL(dw_dma_probe); @@ -1676,6 +1689,8 @@ int dw_dma_remove(struct dw_dma_chip *chip) channel_clear_bit(dw, CH_EN, dwc->mask); } + clk_disable_unprepare(dw->clk); + return 0; } EXPORT_SYMBOL_GPL(dw_dma_remove); -- cgit v1.2.3-55-g7522 From 1222934e54b63752b4b1ad305d6a7f632a3ae46d Mon Sep 17 00:00:00 2001 From: Andy Shevchenko Date: Thu, 8 May 2014 12:01:50 +0300 Subject: dmaengine: dw: check return code of dma_async_device_register() dma_async_device_register() may return non-zero error code. In such case we have to follow error path. Signed-off-by: Andy Shevchenko Signed-off-by: Vinod Koul --- drivers/dma/dw/core.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'drivers/dma/dw') diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c index d539019fbe60..a27ded53ab4f 100644 --- a/drivers/dma/dw/core.c +++ b/drivers/dma/dw/core.c @@ -1659,13 +1659,17 @@ int dw_dma_probe(struct dw_dma_chip *chip, struct dw_dma_platform_data *pdata) dma_writel(dw, CFG, DW_CFG_DMA_EN); + err = dma_async_device_register(&dw->dma); + if (err) + goto err_dma_register; + dev_info(chip->dev, "DesignWare DMA Controller, %d channels\n", nr_channels); - dma_async_device_register(&dw->dma); - return 0; +err_dma_register: + free_irq(chip->irq, dw); err_pdata: clk_disable_unprepare(dw->clk); return err; -- cgit v1.2.3-55-g7522