| Message ID | 20190613005109.1867-1-jassisinghbrar@gmail.com |
|---|---|
| Headers | show |
| Series | Add support for AHB DMA controller on Milbeaut series | expand |
On 12-06-19, 19:52, jassisinghbrar@gmail.com wrote: > +#include <linux/bits.h> > +#include <linux/clk.h> > +#include <linux/dma-mapping.h> > +#include <linux/dmaengine.h> > +#include <linux/interrupt.h> > +#include <linux/iopoll.h> > +#include <linux/list.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/of_dma.h> Do we need both, IIRC of_dma.h does include of.h! > +/* mc->vc.lock must be held by caller */ > +static void milbeaut_chan_start(struct milbeaut_hdmac_chan *mc, > + struct milbeaut_hdmac_desc *md) > +{ > + struct scatterlist *sg; > + u32 cb, ca, src_addr, dest_addr, len; ^^ double space > +static irqreturn_t milbeaut_hdmac_interrupt(int irq, void *dev_id) > +{ > + struct milbeaut_hdmac_chan *mc = dev_id; > + struct milbeaut_hdmac_desc *md; > + irqreturn_t ret = IRQ_HANDLED; > + u32 val; > + > + spin_lock(&mc->vc.lock); > + > + /* Ack and Disable irqs */ > + val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACB); > + val &= ~(FIELD_PREP(MLB_HDMAC_SS, 0x7)); ^^^^ Magic ..? > +static int milbeaut_hdmac_chan_pause(struct dma_chan *chan) > +{ > + struct virt_dma_chan *vc = to_virt_chan(chan); > + struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc); > + u32 val; > + > + spin_lock(&mc->vc.lock); > + val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACA); > + val |= MLB_HDMAC_PB; > + writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACA); We really should have an updatel() and friends in kernel, feel free to add in your driver though! > +static int milbeaut_hdmac_chan_init(struct platform_device *pdev, > + struct milbeaut_hdmac_device *mdev, > + int chan_id) > +{ > + struct device *dev = &pdev->dev; > + struct milbeaut_hdmac_chan *mc = &mdev->channels[chan_id]; > + char *irq_name; > + int irq, ret; > + > + irq = platform_get_irq(pdev, chan_id); > + if (irq < 0) { > + dev_err(&pdev->dev, "failed to get IRQ number for ch%d\n", > + chan_id); > + return irq; > + } > + > + irq_name = devm_kasprintf(dev, GFP_KERNEL, "milbeaut-hdmac-%d", > + chan_id); > + if (!irq_name) > + return -ENOMEM; > + > + ret = devm_request_irq(dev, irq, milbeaut_hdmac_interrupt, > + IRQF_SHARED, irq_name, mc); I tend to dislike using devm_request_irq(), we have no control over when the irq is freed and what is a spirious irq is running while we are unrolling, so IMHO it make sense to free up and ensure all tasklets are quiesced when remove returns > + if (ret) > + return ret; > + > + mc->mdev = mdev; > + mc->reg_ch_base = mdev->reg_base + MLB_HDMAC_CH_STRIDE * (chan_id + 1); > + mc->vc.desc_free = milbeaut_hdmac_desc_free; > + vchan_init(&mc->vc, &mdev->ddev); who kills the vc->task? > +static int milbeaut_hdmac_remove(struct platform_device *pdev) > +{ > + struct milbeaut_hdmac_device *mdev = platform_get_drvdata(pdev); > + struct dma_chan *chan; > + int ret; > + > + /* > + * Before reaching here, almost all descriptors have been freed by the > + * ->device_free_chan_resources() hook. However, each channel might > + * be still holding one descriptor that was on-flight at that moment. > + * Terminate it to make sure this hardware is no longer running. Then, > + * free the channel resources once again to avoid memory leak. > + */ > + list_for_each_entry(chan, &mdev->ddev.channels, device_node) { > + ret = dmaengine_terminate_sync(chan); > + if (ret) > + return ret; > + milbeaut_hdmac_free_chan_resources(chan); > + } > + > + of_dma_controller_free(pdev->dev.of_node); > + dma_async_device_unregister(&mdev->ddev); > + clk_disable_unprepare(mdev->clk); And as suspected we have active tasklets and irq at this time :(
On Mon, Jun 24, 2019 at 1:47 AM Vinod Koul <vkoul@kernel.org> wrote: > > On 12-06-19, 19:52, jassisinghbrar@gmail.com wrote: > > > +#include <linux/bits.h> > > +#include <linux/clk.h> > > +#include <linux/dma-mapping.h> > > +#include <linux/dmaengine.h> > > +#include <linux/interrupt.h> > > +#include <linux/iopoll.h> > > +#include <linux/list.h> > > +#include <linux/module.h> > > +#include <linux/of.h> > > +#include <linux/of_dma.h> > > Do we need both, IIRC of_dma.h does include of.h! > OK > > +/* mc->vc.lock must be held by caller */ > > +static void milbeaut_chan_start(struct milbeaut_hdmac_chan *mc, > > + struct milbeaut_hdmac_desc *md) > > +{ > > + struct scatterlist *sg; > > + u32 cb, ca, src_addr, dest_addr, len; > ^^ > double space > OK > > +static irqreturn_t milbeaut_hdmac_interrupt(int irq, void *dev_id) > > +{ > > + struct milbeaut_hdmac_chan *mc = dev_id; > > + struct milbeaut_hdmac_desc *md; > > + irqreturn_t ret = IRQ_HANDLED; > > + u32 val; > > + > > + spin_lock(&mc->vc.lock); > > + > > + /* Ack and Disable irqs */ > > + val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACB); > > + val &= ~(FIELD_PREP(MLB_HDMAC_SS, 0x7)); > ^^^^ > Magic ..? > OK, will define a macro for 7 > > +static int milbeaut_hdmac_chan_pause(struct dma_chan *chan) > > +{ > > + struct virt_dma_chan *vc = to_virt_chan(chan); > > + struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc); > > + u32 val; > > + > > + spin_lock(&mc->vc.lock); > > + val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACA); > > + val |= MLB_HDMAC_PB; > > + writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACA); > > We really should have an updatel() and friends in kernel, feel free to > add in your driver though! > I'll pass on that for now. > > +static int milbeaut_hdmac_chan_init(struct platform_device *pdev, > > + struct milbeaut_hdmac_device *mdev, > > + int chan_id) > > +{ > > + struct device *dev = &pdev->dev; > > + struct milbeaut_hdmac_chan *mc = &mdev->channels[chan_id]; > > + char *irq_name; > > + int irq, ret; > > + > > + irq = platform_get_irq(pdev, chan_id); > > + if (irq < 0) { > > + dev_err(&pdev->dev, "failed to get IRQ number for ch%d\n", > > + chan_id); > > + return irq; > > + } > > + > > + irq_name = devm_kasprintf(dev, GFP_KERNEL, "milbeaut-hdmac-%d", > > + chan_id); > > + if (!irq_name) > > + return -ENOMEM; > > + > > + ret = devm_request_irq(dev, irq, milbeaut_hdmac_interrupt, > > + IRQF_SHARED, irq_name, mc); > > I tend to dislike using devm_request_irq(), we have no control over when > the irq is freed and what is a spirious irq is running while we are > unrolling, so IMHO it make sense to free up and ensure all tasklets are > quiesced when remove returns > If the code is written clean and tight we need not be so paranoid. > > + if (ret) > > + return ret; > > + > > + mc->mdev = mdev; > > + mc->reg_ch_base = mdev->reg_base + MLB_HDMAC_CH_STRIDE * (chan_id + 1); > > + mc->vc.desc_free = milbeaut_hdmac_desc_free; > > + vchan_init(&mc->vc, &mdev->ddev); > > who kills the vc->task? > vchan_synchronize() called from milbeaut_hdmac_synchronize() > > +static int milbeaut_hdmac_remove(struct platform_device *pdev) > > +{ > > + struct milbeaut_hdmac_device *mdev = platform_get_drvdata(pdev); > > + struct dma_chan *chan; > > + int ret; > > + > > + /* > > + * Before reaching here, almost all descriptors have been freed by the > > + * ->device_free_chan_resources() hook. However, each channel might > > + * be still holding one descriptor that was on-flight at that moment. > > + * Terminate it to make sure this hardware is no longer running. Then, > > + * free the channel resources once again to avoid memory leak. > > + */ > > + list_for_each_entry(chan, &mdev->ddev.channels, device_node) { > > + ret = dmaengine_terminate_sync(chan); > > + if (ret) > > + return ret; > > + milbeaut_hdmac_free_chan_resources(chan); > > + } > > + > > + of_dma_controller_free(pdev->dev.of_node); > > + dma_async_device_unregister(&mdev->ddev); > > + clk_disable_unprepare(mdev->clk); > > And as suspected we have active tasklets and irq at this time :( > Not sure how is that.... thanks.
On 15-08-19, 21:25, Jassi Brar wrote: > On Mon, Jun 24, 2019 at 1:47 AM Vinod Koul <vkoul@kernel.org> wrote: > > > > On 12-06-19, 19:52, jassisinghbrar@gmail.com wrote: > > > > > +#include <linux/bits.h> > > > +#include <linux/clk.h> > > > +#include <linux/dma-mapping.h> > > > +#include <linux/dmaengine.h> > > > +#include <linux/interrupt.h> > > > +#include <linux/iopoll.h> > > > +#include <linux/list.h> > > > +#include <linux/module.h> > > > +#include <linux/of.h> > > > +#include <linux/of_dma.h> > > > > Do we need both, IIRC of_dma.h does include of.h! > > > OK > > > > +/* mc->vc.lock must be held by caller */ > > > +static void milbeaut_chan_start(struct milbeaut_hdmac_chan *mc, > > > + struct milbeaut_hdmac_desc *md) > > > +{ > > > + struct scatterlist *sg; > > > + u32 cb, ca, src_addr, dest_addr, len; > > ^^ > > double space > > > OK > > > > +static irqreturn_t milbeaut_hdmac_interrupt(int irq, void *dev_id) > > > +{ > > > + struct milbeaut_hdmac_chan *mc = dev_id; > > > + struct milbeaut_hdmac_desc *md; > > > + irqreturn_t ret = IRQ_HANDLED; > > > + u32 val; > > > + > > > + spin_lock(&mc->vc.lock); > > > + > > > + /* Ack and Disable irqs */ > > > + val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACB); > > > + val &= ~(FIELD_PREP(MLB_HDMAC_SS, 0x7)); > > ^^^^ > > Magic ..? > > > OK, will define a macro for 7 > > > > +static int milbeaut_hdmac_chan_pause(struct dma_chan *chan) > > > +{ > > > + struct virt_dma_chan *vc = to_virt_chan(chan); > > > + struct milbeaut_hdmac_chan *mc = to_milbeaut_hdmac_chan(vc); > > > + u32 val; > > > + > > > + spin_lock(&mc->vc.lock); > > > + val = readl_relaxed(mc->reg_ch_base + MLB_HDMAC_DMACA); > > > + val |= MLB_HDMAC_PB; > > > + writel_relaxed(val, mc->reg_ch_base + MLB_HDMAC_DMACA); > > > > We really should have an updatel() and friends in kernel, feel free to > > add in your driver though! > > > I'll pass on that for now. > > > > +static int milbeaut_hdmac_chan_init(struct platform_device *pdev, > > > + struct milbeaut_hdmac_device *mdev, > > > + int chan_id) > > > +{ > > > + struct device *dev = &pdev->dev; > > > + struct milbeaut_hdmac_chan *mc = &mdev->channels[chan_id]; > > > + char *irq_name; > > > + int irq, ret; > > > + > > > + irq = platform_get_irq(pdev, chan_id); > > > + if (irq < 0) { > > > + dev_err(&pdev->dev, "failed to get IRQ number for ch%d\n", > > > + chan_id); > > > + return irq; > > > + } > > > + > > > + irq_name = devm_kasprintf(dev, GFP_KERNEL, "milbeaut-hdmac-%d", > > > + chan_id); > > > + if (!irq_name) > > > + return -ENOMEM; > > > + > > > + ret = devm_request_irq(dev, irq, milbeaut_hdmac_interrupt, > > > + IRQF_SHARED, irq_name, mc); > > > > I tend to dislike using devm_request_irq(), we have no control over when > > the irq is freed and what is a spirious irq is running while we are > > unrolling, so IMHO it make sense to free up and ensure all tasklets are > > quiesced when remove returns > > > If the code is written clean and tight we need not be so paranoid. > > > > + if (ret) > > > + return ret; > > > + > > > + mc->mdev = mdev; > > > + mc->reg_ch_base = mdev->reg_base + MLB_HDMAC_CH_STRIDE * (chan_id + 1); > > > + mc->vc.desc_free = milbeaut_hdmac_desc_free; > > > + vchan_init(&mc->vc, &mdev->ddev); > > > > who kills the vc->task? > > > vchan_synchronize() called from milbeaut_hdmac_synchronize() But that can be skipped by called, from driver pov we need to ensure that it is killed > > > +static int milbeaut_hdmac_remove(struct platform_device *pdev) > > > +{ > > > + struct milbeaut_hdmac_device *mdev = platform_get_drvdata(pdev); > > > + struct dma_chan *chan; > > > + int ret; > > > + > > > + /* > > > + * Before reaching here, almost all descriptors have been freed by the > > > + * ->device_free_chan_resources() hook. However, each channel might > > > + * be still holding one descriptor that was on-flight at that moment. > > > + * Terminate it to make sure this hardware is no longer running. Then, > > > + * free the channel resources once again to avoid memory leak. > > > + */ > > > + list_for_each_entry(chan, &mdev->ddev.channels, device_node) { > > > + ret = dmaengine_terminate_sync(chan); > > > + if (ret) > > > + return ret; > > > + milbeaut_hdmac_free_chan_resources(chan); > > > + } > > > + > > > + of_dma_controller_free(pdev->dev.of_node); > > > + dma_async_device_unregister(&mdev->ddev); > > > + clk_disable_unprepare(mdev->clk); > > > > And as suspected we have active tasklets and irq at this time :( > > > Not sure how is that.... Since you use devm variants, and driver tasklet is not killed, irq can be fired (spurious as well) and can run irq and schedule a tasklet. How do you prevent that? Thanks
From: Jassi Brar <jaswinder.singh@linaro.org> The following series adds AHB DMA (HDMAC) controller support on Milbeaut series. This controller is capable of Mem<->MEM and DEV<->MEM transfer. But only DEV<->MEM is currently supported. Jassi Brar (2): dt-bindings: milbeaut-hdmac: Add Socionext Milbeaut HDMAC bindings dmaengine: milbeaut-hdmac: Add HDMAC driver for Milbeaut platforms .../bindings/dma/milbeaut-m10v-hdmac.txt | 54 ++ drivers/dma/Kconfig | 10 + drivers/dma/Makefile | 1 + drivers/dma/milbeaut-hdmac.c | 572 ++++++++++++++++++ 4 files changed, 637 insertions(+) create mode 100644 Documentation/devicetree/bindings/dma/milbeaut-m10v-hdmac.txt create mode 100644 drivers/dma/milbeaut-hdmac.c