| Message ID | 4c7f98c86ad.343ea8c1@auth.smtp.1and1.co.uk (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Scott Wood |
| Headers | show |
| Series | [RFC] powerpc/kernel: Don't check for dev->dma_mask in fsl_set_dma_mask | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | next/apply_patch Successfully applied |
| snowpatch_ozlabs/checkpatch | success | Test checkpatch on branch next |
| snowpatch_ozlabs/build-ppc64le | fail | Test build-ppc64le on branch next |
| snowpatch_ozlabs/build-ppc64be | fail | Test build-ppc64be on branch next |
| snowpatch_ozlabs/build-ppc64e | fail | Test build-ppc64e on branch next |
| snowpatch_ozlabs/build-ppc32 | fail | Test build-ppc32 on branch next |
Hi, Your patch should be sent as part of the message text and not as an attached file. By sending as an attached file, patchwork doesn't handle it properly (all compilation tests fail) https://patchwork.ozlabs.org/patch/965082/ For reference, see https://www.kernel.org/doc/html/latest/process/submitting-patches.html#no-mime-no-links-no-compression-no-attachments-just-plain-text Christophe Le 02/09/2018 à 13:30, Darren Stevens a écrit : > To enable use of dma to all ram on a corenet generic system, we add the > function fsl_pci_dma_set_mask, and link it into the ppc.md structure. > > But this function checks for the presence of dev->dma_mask and dma_ops > at entry, and fails if one or other are missing. Powerpc's dma_set_mask > (which it is called from) doesn't check this until after it has set the > dma_mask for pci devs, this difference shows up on a Cyrus (AmigaOne X5000) > - a soundblaster live pci card, will works properly if memory is limited > to <4G, but fail on probe with the following message if the memory is >=4G > > [ 4.646531] snd_emu10k1 1000:04:04.0: architecture does not support PCI > busmaster DMA with mask 0x7fffffff > > Remove the dev->mask tests to make the routines behave similarly. > > Signed-off-by: Darren Stevens <darren@stevens-zone.net> > > --- > > This fix looks wrong to me, although it works. The test needs to be removed, > moving it to the end of the function doesn't work either. This needs someone > with more knowledge of what's going on to take a look. >
On Sun, 2018-09-02 at 12:30 +0100, Darren Stevens wrote: > To enable use of dma to all ram on a corenet generic system, we add the > function fsl_pci_dma_set_mask, and link it into the ppc.md structure. > > But this function checks for the presence of dev->dma_mask and dma_ops > at entry, and fails if one or other are missing. Powerpc's dma_set_mask > (which it is called from) doesn't check this until after it has set the > dma_mask for pci devs, It's checking whether the dma_mask pointer is valid before storing into that pointer. The generic ppc dma_set_mask does check this before storing into it. All it does before that check is to look for an alternative dma_set_mask implementation. Is the test failing on dma_mask or dma_supported? If the latter, what are the dma ops set to? Can you check whether the problem still exists after commit ff69279a44e9ba876466 ("powerpc: disable support for relative ksymtab references")? -Scott
diff --git a/arch/powerpc/sysdev/fsl_pci.c b/arch/powerpc/sysdev/fsl_pci.c index 918be81..36b3c86 100644 --- a/arch/powerpc/sysdev/fsl_pci.c +++ b/arch/powerpc/sysdev/fsl_pci.c @@ -127,9 +127,6 @@ static inline void setup_swiotlb_ops(struct pci_controller *hose) {} static int fsl_pci_dma_set_mask(struct device *dev, u64 dma_mask) { - if (!dev->dma_mask || !dma_supported(dev, dma_mask)) - return -EIO; - /* * Fix up PCI devices that are able to DMA to the large inbound * mapping that allows addressing any RAM address from across PCI.
To enable use of dma to all ram on a corenet generic system, we add the function fsl_pci_dma_set_mask, and link it into the ppc.md structure. But this function checks for the presence of dev->dma_mask and dma_ops at entry, and fails if one or other are missing. Powerpc's dma_set_mask (which it is called from) doesn't check this until after it has set the dma_mask for pci devs, this difference shows up on a Cyrus (AmigaOne X5000) - a soundblaster live pci card, will works properly if memory is limited to <4G, but fail on probe with the following message if the memory is >=4G [ 4.646531] snd_emu10k1 1000:04:04.0: architecture does not support PCI busmaster DMA with mask 0x7fffffff Remove the dev->mask tests to make the routines behave similarly. Signed-off-by: Darren Stevens <darren@stevens-zone.net> --- This fix looks wrong to me, although it works. The test needs to be removed, moving it to the end of the function doesn't work either. This needs someone with more knowledge of what's going on to take a look.