Messages in this thread | | | Date | Mon, 25 Feb 2008 00:31:00 -0700 | From | Grant Grundler <> | Subject | Re: [PATCH 03/10] PCI: AMD SATA IDE mode quirk |
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On Mon, Feb 25, 2008 at 09:43:59AM +0800, Cai, Crane wrote: > > On Fri, Feb 22, 2008 at 01:49:20PM +0800, Cai, Crane wrote: > > > > On Thu, Feb 21, 2008 at 03:47:33PM -0800, Greg > > Kroah-Hartman wrote: > > > > > +static void __devinit quirk_amd_ide_mode(struct pci_dev *pdev) > > > > > { > > > > > - /* set sb600 sata to ahci mode */ > > > > > - if ((pdev->class >> 8) == PCI_CLASS_STORAGE_IDE) { > > > > > - u8 tmp; > > > > > + /* set sb600/sb700/sb800 sata to ahci mode */ > > > > > + u8 tmp; > > > > > > > > > > + pci_read_config_byte(pdev, PCI_CLASS_DEVICE, &tmp); > > > > > + if (tmp == 0x01) { > > > > > pci_read_config_byte(pdev, 0x40, &tmp); > > > > > > > > This seems like a dis-improvement. Why are we reading a > > config byte > > > > for something we already have in the pci_dev? > > > > Why are we now checking against 0x01 instead of a > > symbolic constant? > > > > Why are we no longer checking that this is PCI_BASE_CLASS_STORAGE? > > > It is a quirk. In pci_ids.h did have PCI_CLASS_STORAGE_IDE and > > > PCI_BASE_CLASS_STORAGE, these can not represent the right > > situation we > > > want to check. 0x01 represents PCI_CLASS_STORAGE_IDE last 2 > > bit. Also > > > because it is a quirk, I do not think we need to change > > pci_ids.h. So > > > 0x01 used. > > > > You haven't explained what is wrong with the original code: > > > > if ((pdev->class >> 8) == PCI_CLASS_STORAGE_IDE) { > > > > When resume, this pdev->class is quirked, however BIOS has > modified pci configuration too. Inconsistance occurs.
Can you update pdev->class from the quirk? It would be consistent then. That would leave the code as-is except it's re-reading the field from config space.
hth, grant
> > > > Nothing in the changelog entry suggests why we now need > > FIXUP_RESUME > > > > entries when we didn't before. > > > > > > > PCI configuration space will be changed by BIOS and then in > > pci init > > > and restore. So resume also needed. > > > > That information needed to be in the changelog. > > This info, is a normal info. If maintainer need us to added in source code. I preferred too. > > -- > > Intel are signing my paycheques ... these opinions are still > > mine "Bill, look, we understand that you're interested in > > selling us this operating system, but compare it to ours. We > > can't possibly take such a retrograde step." > > > > > >
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