| Message ID | d485dc3698304403620d5ed92d066942a6b68cfd.1536770587.git.robin.murphy@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | media: s5p-mfc: Fix memdev DMA configuration | expand |
Hi Robin, On 2018-09-12 18:45, Robin Murphy wrote: > Having of_reserved_mem_device_init() forcibly reconfigure DMA for all > callers, potentially overriding the work done by a bus-specific > .dma_configure method earlier, is at best a bad idea and at worst > actively harmful. If drivers really need virtual devices to own > dma-coherent memory, they should explicitly configure those devices > based on the appropriate firmware node as they create them. > > It looks like the only driver not passing in a proper OF platform device > is s5p-mfc, so move the rogue of_dma_configure() call into that driver > where it logically belongs. > > CC: Smitha T Murthy <smitha.t@samsung.com> > CC: Marek Szyprowski <m.szyprowski@samsung.com> > CC: Rob Herring <robh@kernel.org> > Signed-off-by: Robin Murphy <robin.murphy@arm.com> Right, after recent cleanup dma ops initialization, MFC driver is a better place for calling of_dma_configure() on virtual devices. Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> > --- > drivers/media/platform/s5p-mfc/s5p_mfc.c | 7 +++++++ > drivers/of/of_reserved_mem.c | 4 ---- > 2 files changed, 7 insertions(+), 4 deletions(-) > > diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c b/drivers/media/platform/s5p-mfc/s5p_mfc.c > index 927a1235408d..77eb4a4511c1 100644 > --- a/drivers/media/platform/s5p-mfc/s5p_mfc.c > +++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c > @@ -1094,6 +1094,13 @@ static struct device *s5p_mfc_alloc_memdev(struct device *dev, > child->dma_mask = dev->dma_mask; > child->release = s5p_mfc_memdev_release; > > + /* > + * The memdevs are not proper OF platform devices, so in order for them > + * to be treated as valid DMA masters we need a bit of a hack to force > + * them to inherit the MFC node's DMA configuration. > + */ > + of_dma_configure(child, dev->of_node, true); > + > if (device_add(child) == 0) { > ret = of_reserved_mem_device_init_by_idx(child, dev->of_node, > idx); > diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c > index 895c83e0c7b6..4ef6f4485335 100644 > --- a/drivers/of/of_reserved_mem.c > +++ b/drivers/of/of_reserved_mem.c > @@ -350,10 +350,6 @@ int of_reserved_mem_device_init_by_idx(struct device *dev, > mutex_lock(&of_rmem_assigned_device_mutex); > list_add(&rd->list, &of_rmem_assigned_device_list); > mutex_unlock(&of_rmem_assigned_device_mutex); > - /* ensure that dma_ops is set for virtual devices > - * using reserved memory > - */ > - of_dma_configure(dev, np, true); > > dev_info(dev, "assigned reserved memory node %s\n", rmem->name); > } else { Best regards
Em Fri, 14 Sep 2018 14:19:29 +0200 Marek Szyprowski <m.szyprowski@samsung.com> escreveu: > Hi Robin, > > On 2018-09-12 18:45, Robin Murphy wrote: > > Having of_reserved_mem_device_init() forcibly reconfigure DMA for all > > callers, potentially overriding the work done by a bus-specific > > .dma_configure method earlier, is at best a bad idea and at worst > > actively harmful. If drivers really need virtual devices to own > > dma-coherent memory, they should explicitly configure those devices > > based on the appropriate firmware node as they create them. > > > > It looks like the only driver not passing in a proper OF platform device > > is s5p-mfc, so move the rogue of_dma_configure() call into that driver > > where it logically belongs. > > > > CC: Smitha T Murthy <smitha.t@samsung.com> > > CC: Marek Szyprowski <m.szyprowski@samsung.com> > > CC: Rob Herring <robh@kernel.org> > > Signed-off-by: Robin Murphy <robin.murphy@arm.com> > > Right, after recent cleanup dma ops initialization, MFC driver is > a better place for calling of_dma_configure() on virtual devices. > > Reviewed-by: Marek Szyprowski <m.szyprowski@samsung.com> This patch seems to fit better via OF/DT tree. Not sure if it was merged there yet. In any case: Acked-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> > > > --- > > drivers/media/platform/s5p-mfc/s5p_mfc.c | 7 +++++++ > > drivers/of/of_reserved_mem.c | 4 ---- > > 2 files changed, 7 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c b/drivers/media/platform/s5p-mfc/s5p_mfc.c > > index 927a1235408d..77eb4a4511c1 100644 > > --- a/drivers/media/platform/s5p-mfc/s5p_mfc.c > > +++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c > > @@ -1094,6 +1094,13 @@ static struct device *s5p_mfc_alloc_memdev(struct device *dev, > > child->dma_mask = dev->dma_mask; > > child->release = s5p_mfc_memdev_release; > > > > + /* > > + * The memdevs are not proper OF platform devices, so in order for them > > + * to be treated as valid DMA masters we need a bit of a hack to force > > + * them to inherit the MFC node's DMA configuration. > > + */ > > + of_dma_configure(child, dev->of_node, true); > > + > > if (device_add(child) == 0) { > > ret = of_reserved_mem_device_init_by_idx(child, dev->of_node, > > idx); > > diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c > > index 895c83e0c7b6..4ef6f4485335 100644 > > --- a/drivers/of/of_reserved_mem.c > > +++ b/drivers/of/of_reserved_mem.c > > @@ -350,10 +350,6 @@ int of_reserved_mem_device_init_by_idx(struct device *dev, > > mutex_lock(&of_rmem_assigned_device_mutex); > > list_add(&rd->list, &of_rmem_assigned_device_list); > > mutex_unlock(&of_rmem_assigned_device_mutex); > > - /* ensure that dma_ops is set for virtual devices > > - * using reserved memory > > - */ > > - of_dma_configure(dev, np, true); > > > > dev_info(dev, "assigned reserved memory node %s\n", rmem->name); > > } else { > > Best regards Thanks, Mauro
diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c b/drivers/media/platform/s5p-mfc/s5p_mfc.c index 927a1235408d..77eb4a4511c1 100644 --- a/drivers/media/platform/s5p-mfc/s5p_mfc.c +++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c @@ -1094,6 +1094,13 @@ static struct device *s5p_mfc_alloc_memdev(struct device *dev, child->dma_mask = dev->dma_mask; child->release = s5p_mfc_memdev_release; + /* + * The memdevs are not proper OF platform devices, so in order for them + * to be treated as valid DMA masters we need a bit of a hack to force + * them to inherit the MFC node's DMA configuration. + */ + of_dma_configure(child, dev->of_node, true); + if (device_add(child) == 0) { ret = of_reserved_mem_device_init_by_idx(child, dev->of_node, idx); diff --git a/drivers/of/of_reserved_mem.c b/drivers/of/of_reserved_mem.c index 895c83e0c7b6..4ef6f4485335 100644 --- a/drivers/of/of_reserved_mem.c +++ b/drivers/of/of_reserved_mem.c @@ -350,10 +350,6 @@ int of_reserved_mem_device_init_by_idx(struct device *dev, mutex_lock(&of_rmem_assigned_device_mutex); list_add(&rd->list, &of_rmem_assigned_device_list); mutex_unlock(&of_rmem_assigned_device_mutex); - /* ensure that dma_ops is set for virtual devices - * using reserved memory - */ - of_dma_configure(dev, np, true); dev_info(dev, "assigned reserved memory node %s\n", rmem->name); } else {
Having of_reserved_mem_device_init() forcibly reconfigure DMA for all callers, potentially overriding the work done by a bus-specific .dma_configure method earlier, is at best a bad idea and at worst actively harmful. If drivers really need virtual devices to own dma-coherent memory, they should explicitly configure those devices based on the appropriate firmware node as they create them. It looks like the only driver not passing in a proper OF platform device is s5p-mfc, so move the rogue of_dma_configure() call into that driver where it logically belongs. CC: Smitha T Murthy <smitha.t@samsung.com> CC: Marek Szyprowski <m.szyprowski@samsung.com> CC: Rob Herring <robh@kernel.org> Signed-off-by: Robin Murphy <robin.murphy@arm.com> --- drivers/media/platform/s5p-mfc/s5p_mfc.c | 7 +++++++ drivers/of/of_reserved_mem.c | 4 ---- 2 files changed, 7 insertions(+), 4 deletions(-)