| Message ID | 20190121101121.24555-1-zajec5@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | [wireless-drivers-next] bcma: get SoC device struct & copy its DMA params to the subdevices | expand |
On Mon, Jan 21, 2019 at 11:11:21AM +0100, Rafał Miłecki wrote: > From: Rafał Miłecki <rafal@milecki.pl> > > For bus devices to be fully usable it's required to set their DMA > parameters. > > For years it has been missing and remained unnoticed because of > mips_dma_alloc_coherent() silently handling the empty coherent_dma_mask. > Kernel 4.19 came with a lot of DMA changes and caused a regression on > the bcm47xx. Starting with the commit f8c55dc6e828 ("MIPS: use generic > dma noncoherent ops for simple noncoherent platforms") DMA coherent > allocations just fail. Example: > [ 1.114914] bgmac_bcma bcma0:2: Allocation of TX ring 0x200 failed > [ 1.121215] bgmac_bcma bcma0:2: Unable to alloc memory for DMA > [ 1.127626] bgmac_bcma: probe of bcma0:2 failed with error -12 > [ 1.133838] bgmac_bcma: Broadcom 47xx GBit MAC driver loaded > > This change fixes above regression in addition to the MIPS bcm47xx > commit 321c46b91550 ("MIPS: BCM47XX: Setup struct device for the SoC"). > > It also fixes another *old* GPIO regression caused by a parent pointing > to the NULL: > [ 0.157054] missing gpiochip .dev parent pointer > [ 0.157287] bcma: bus0: Error registering GPIO driver: -22 > introduced by the commit 74f4e0cc6108 ("bcma: switch GPIO portions to > use GPIOLIB_IRQCHIP"). > > Fixes: f8c55dc6e828 ("MIPS: use generic dma noncoherent ops for simple noncoherent platforms") > Fixes: 74f4e0cc6108 ("bcma: switch GPIO portions to use GPIOLIB_IRQCHIP") > Cc: linux-mips@linux-mips.org > Cc: Christoph Hellwig <hch@lst.de> > Cc: Linus Walleij <linus.walleij@linaro.org> > Signed-off-by: Rafał Miłecki <rafal@milecki.pl> > --- > While this patch is a regression fix, it depends on a change present in > the wireless-drivers-next.git: > bcma: keep a direct pointer to the struct device > > That's why I suggest pushing it into the wireless-drivers-next.git and I > can take care of picking it for the stable@kernel.org later. > > Another option would be cherry-picking commit 5a1c18b761dd ("bcma: keep > a direct pointer to the struct device") to the wireless-drivers.git but > I don't think it's a common practice. > --- > drivers/bcma/host_soc.c | 2 ++ > drivers/bcma/main.c | 6 +++++- > include/linux/bcma/bcma_soc.h | 1 + > 3 files changed, 8 insertions(+), 1 deletion(-) > > diff --git a/drivers/bcma/host_soc.c b/drivers/bcma/host_soc.c > index c8073b509a2b..1fdfb704f22d 100644 > --- a/drivers/bcma/host_soc.c > +++ b/drivers/bcma/host_soc.c > @@ -191,6 +191,8 @@ int __init bcma_host_soc_init(struct bcma_soc *soc) > struct bcma_bus *bus = &soc->bus; > int err; > > + bus->dev = soc->dev; > + > /* Scan bus and initialize it */ > err = bcma_bus_early_register(bus); > if (err) > diff --git a/drivers/bcma/main.c b/drivers/bcma/main.c > index 6535614a7dc1..433ca5e2ed2c 100644 > --- a/drivers/bcma/main.c > +++ b/drivers/bcma/main.c > @@ -236,12 +236,16 @@ EXPORT_SYMBOL(bcma_core_irq); > > void bcma_prepare_core(struct bcma_bus *bus, struct bcma_device *core) > { > + struct device *dev = &core->dev; > + > core->dev.release = bcma_release_core_dev; > core->dev.bus = &bcma_bus_type; > dev_set_name(&core->dev, "bcma%d:%d", bus->num, core->core_index); > core->dev.parent = bus->dev; > - if (bus->dev) > + if (bus->dev) { > bcma_of_fill_device(bus->dev, core); > + dma_coerce_mask_and_coherent(dev, bus->dev->coherent_dma_mask); > + } I don't think this does the right thing for bcma devices behind PCI/PCIe, as those might need a IOMMU which relies on having a device it has properly enumerated to be passed into the DMA API. In other words: I think you need to change the layering so that the DMA API is always called on the underlying PCI/PCIe/platform device, not of the child bus.
On Mon, 21 Jan 2019 at 15:46, Christoph Hellwig <hch@lst.de> wrote: > On Mon, Jan 21, 2019 at 11:11:21AM +0100, Rafał Miłecki wrote: > > From: Rafał Miłecki <rafal@milecki.pl> > > > > For bus devices to be fully usable it's required to set their DMA > > parameters. > > > > For years it has been missing and remained unnoticed because of > > mips_dma_alloc_coherent() silently handling the empty coherent_dma_mask. > > Kernel 4.19 came with a lot of DMA changes and caused a regression on > > the bcm47xx. Starting with the commit f8c55dc6e828 ("MIPS: use generic > > dma noncoherent ops for simple noncoherent platforms") DMA coherent > > allocations just fail. Example: > > [ 1.114914] bgmac_bcma bcma0:2: Allocation of TX ring 0x200 failed > > [ 1.121215] bgmac_bcma bcma0:2: Unable to alloc memory for DMA > > [ 1.127626] bgmac_bcma: probe of bcma0:2 failed with error -12 > > [ 1.133838] bgmac_bcma: Broadcom 47xx GBit MAC driver loaded > > > > This change fixes above regression in addition to the MIPS bcm47xx > > commit 321c46b91550 ("MIPS: BCM47XX: Setup struct device for the SoC"). > > > > It also fixes another *old* GPIO regression caused by a parent pointing > > to the NULL: > > [ 0.157054] missing gpiochip .dev parent pointer > > [ 0.157287] bcma: bus0: Error registering GPIO driver: -22 > > introduced by the commit 74f4e0cc6108 ("bcma: switch GPIO portions to > > use GPIOLIB_IRQCHIP"). > > > > Fixes: f8c55dc6e828 ("MIPS: use generic dma noncoherent ops for simple noncoherent platforms") > > Fixes: 74f4e0cc6108 ("bcma: switch GPIO portions to use GPIOLIB_IRQCHIP") > > Cc: linux-mips@linux-mips.org > > Cc: Christoph Hellwig <hch@lst.de> > > Cc: Linus Walleij <linus.walleij@linaro.org> > > Signed-off-by: Rafał Miłecki <rafal@milecki.pl> > > --- > > While this patch is a regression fix, it depends on a change present in > > the wireless-drivers-next.git: > > bcma: keep a direct pointer to the struct device > > > > That's why I suggest pushing it into the wireless-drivers-next.git and I > > can take care of picking it for the stable@kernel.org later. > > > > Another option would be cherry-picking commit 5a1c18b761dd ("bcma: keep > > a direct pointer to the struct device") to the wireless-drivers.git but > > I don't think it's a common practice. > > --- > > drivers/bcma/host_soc.c | 2 ++ > > drivers/bcma/main.c | 6 +++++- > > include/linux/bcma/bcma_soc.h | 1 + > > 3 files changed, 8 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/bcma/host_soc.c b/drivers/bcma/host_soc.c > > index c8073b509a2b..1fdfb704f22d 100644 > > --- a/drivers/bcma/host_soc.c > > +++ b/drivers/bcma/host_soc.c > > @@ -191,6 +191,8 @@ int __init bcma_host_soc_init(struct bcma_soc *soc) > > struct bcma_bus *bus = &soc->bus; > > int err; > > > > + bus->dev = soc->dev; > > + > > /* Scan bus and initialize it */ > > err = bcma_bus_early_register(bus); > > if (err) > > diff --git a/drivers/bcma/main.c b/drivers/bcma/main.c > > index 6535614a7dc1..433ca5e2ed2c 100644 > > --- a/drivers/bcma/main.c > > +++ b/drivers/bcma/main.c > > @@ -236,12 +236,16 @@ EXPORT_SYMBOL(bcma_core_irq); > > > > void bcma_prepare_core(struct bcma_bus *bus, struct bcma_device *core) > > { > > + struct device *dev = &core->dev; > > + > > core->dev.release = bcma_release_core_dev; > > core->dev.bus = &bcma_bus_type; > > dev_set_name(&core->dev, "bcma%d:%d", bus->num, core->core_index); > > core->dev.parent = bus->dev; > > - if (bus->dev) > > + if (bus->dev) { > > bcma_of_fill_device(bus->dev, core); > > + dma_coerce_mask_and_coherent(dev, bus->dev->coherent_dma_mask); > > + } > > I don't think this does the right thing for bcma devices behind > PCI/PCIe, as those might need a IOMMU which relies on having a device > it has properly enumerated to be passed into the DMA API. In other > words: I think you need to change the layering so that the DMA API > is always called on the underlying PCI/PCIe/platform device, not of > the child bus. This is already implemented (we have dma_dev pointer), but it may be indeed more correct to apply this change for the SoC code only. I'll send V2.
On 1/21/2019 2:11 AM, RafaB MiBecki wrote: > From: Rafał Miłecki <rafal@milecki.pl> > > For bus devices to be fully usable it's required to set their DMA > parameters. > > For years it has been missing and remained unnoticed because of > mips_dma_alloc_coherent() silently handling the empty coherent_dma_mask. > Kernel 4.19 came with a lot of DMA changes and caused a regression on > the bcm47xx. Starting with the commit f8c55dc6e828 ("MIPS: use generic > dma noncoherent ops for simple noncoherent platforms") DMA coherent > allocations just fail. Example: > [ 1.114914] bgmac_bcma bcma0:2: Allocation of TX ring 0x200 failed > [ 1.121215] bgmac_bcma bcma0:2: Unable to alloc memory for DMA > [ 1.127626] bgmac_bcma: probe of bcma0:2 failed with error -12 > [ 1.133838] bgmac_bcma: Broadcom 47xx GBit MAC driver loaded > > This change fixes above regression in addition to the MIPS bcm47xx > commit 321c46b91550 ("MIPS: BCM47XX: Setup struct device for the SoC"). > > It also fixes another *old* GPIO regression caused by a parent pointing > to the NULL: > [ 0.157054] missing gpiochip .dev parent pointer > [ 0.157287] bcma: bus0: Error registering GPIO driver: -22 > introduced by the commit 74f4e0cc6108 ("bcma: switch GPIO portions to > use GPIOLIB_IRQCHIP"). > > Fixes: f8c55dc6e828 ("MIPS: use generic dma noncoherent ops for simple noncoherent platforms") > Fixes: 74f4e0cc6108 ("bcma: switch GPIO portions to use GPIOLIB_IRQCHIP") > Cc: linux-mips@linux-mips.org > Cc: Christoph Hellwig <hch@lst.de> > Cc: Linus Walleij <linus.walleij@linaro.org> > Signed-off-by: Rafał Miłecki <rafal@milecki.pl> > --- > While this patch is a regression fix, it depends on a change present in > the wireless-drivers-next.git: > bcma: keep a direct pointer to the struct device Rafal, there was supposed to be a v2, but I could not find one, this is the regression that prevented bgmac_bcma from loading while testing upstream, did you have a v2 ready already to be submitted somehow? Thanks!
Please Cc me on the next version. Copying over dma parameters sounds like the wrong thing to do.
diff --git a/drivers/bcma/host_soc.c b/drivers/bcma/host_soc.c index c8073b509a2b..1fdfb704f22d 100644 --- a/drivers/bcma/host_soc.c +++ b/drivers/bcma/host_soc.c @@ -191,6 +191,8 @@ int __init bcma_host_soc_init(struct bcma_soc *soc) struct bcma_bus *bus = &soc->bus; int err; + bus->dev = soc->dev; + /* Scan bus and initialize it */ err = bcma_bus_early_register(bus); if (err) diff --git a/drivers/bcma/main.c b/drivers/bcma/main.c index 6535614a7dc1..433ca5e2ed2c 100644 --- a/drivers/bcma/main.c +++ b/drivers/bcma/main.c @@ -236,12 +236,16 @@ EXPORT_SYMBOL(bcma_core_irq); void bcma_prepare_core(struct bcma_bus *bus, struct bcma_device *core) { + struct device *dev = &core->dev; + core->dev.release = bcma_release_core_dev; core->dev.bus = &bcma_bus_type; dev_set_name(&core->dev, "bcma%d:%d", bus->num, core->core_index); core->dev.parent = bus->dev; - if (bus->dev) + if (bus->dev) { bcma_of_fill_device(bus->dev, core); + dma_coerce_mask_and_coherent(dev, bus->dev->coherent_dma_mask); + } switch (bus->hosttype) { case BCMA_HOSTTYPE_PCI: diff --git a/include/linux/bcma/bcma_soc.h b/include/linux/bcma/bcma_soc.h index 7cca5f859a90..f3c43519baa7 100644 --- a/include/linux/bcma/bcma_soc.h +++ b/include/linux/bcma/bcma_soc.h @@ -6,6 +6,7 @@ struct bcma_soc { struct bcma_bus bus; + struct device *dev; }; int __init bcma_host_soc_register(struct bcma_soc *soc);