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 <redacted>
---
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.
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 <redacted>
---
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