On Mon, Mar 22, 2021 at 04:18:23PM +0100, Christoph Hellwig wrote:
On Mon, Mar 22, 2021 at 03:15:03PM +0000, Russell King - ARM Linux admin wrote:
It gets worse than that though - due to a change to remove
pcibios_min_io from the generic code, moving it into the ARM
architecture code, this has caused a regression that prevents the
legacy resources being registered against the bus resource. So even
if they are there, they cause probe failures. I haven't found a
reasonable way to solve this yet, but until there is, there is no
way that the PATA driver can be used as the "legacy mode" support
is effectively done via the PCI code assigning virtual IO port
resources.
I'm quite surprised that the CY82C693 even works on Alpha - I've
asked for a lspci for that last week but nothing has yet been
forthcoming from whoever responded to your patch for Alpha - so I
can't compare what I'm seeing with what's happening with Alpha.
That sounds like something we could fix with a quirk for function 2
in the PCI resource assignment code. Can you show what vendor and
device ID function 2 has so that I could try to come up with one?
Something like this:
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 953f15abc850ac..851918206c4f2d 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1855,7 +1855,7 @@ int pci_setup_device(struct pci_dev *dev)
* addresses. These are not always echoed in BAR0-3, and
* BAR0-3 in a few cases contain junk!
*/
- if (class == PCI_CLASS_STORAGE_IDE) {
+ if (class == PCI_CLASS_STORAGE_IDE && !dev->no_legacy_ide_bars) {
u8 progif;
pci_read_config_byte(dev, PCI_CLASS_PROG, &progif);
if ((progif & 1) == 0) {
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 653660e3ba9ef1..c661462d894a5b 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5612,3 +5612,16 @@ static void apex_pci_fixup_class(struct pci_dev *pdev)
}
DECLARE_PCI_FIXUP_CLASS_HEADER(0x1ac1, 0x089a,
PCI_CLASS_NOT_DEFINED, 8, apex_pci_fixup_class);
+
+/*
+ * CY82C693 splits the primary and secondar IDE channels over 2 functions, which
+ * causes the PCI resource assignment algorithm to assign the legacy IDE I/O
+ * regions to both of them. Disable that assignment for function 2 here.
+ */
+static void quirk_cy82c693_legacy_resources(struct pci_dev *pdev)
+{
+ if (PCI_FUNC(pdev->devfn) == 2)
+ pdev->no_legacy_ide_bars = 1;
+}
+DECLARE_PCI_FIXUP_FINAL(PCI_VENDOR_ID_CONTAQ, PCI_DEVICE_ID_CONTAQ_82C693,
+ quirk_cy82c693_legacy_resources);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 86c799c97b7796..7ca3f5ebbfade7 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -453,6 +453,7 @@ struct pci_dev {
unsigned int link_active_reporting:1;/* Device capable of reporting link active */
unsigned int no_vf_scan:1; /* Don't scan for VFs after IOV enablement */
unsigned int no_command_memory:1; /* No PCI_COMMAND_MEMORY */
+ unsigned int no_legacy_ide_bars:1; /* do not assign legacy IDE BARs */
pci_dev_flags_t dev_flags;
atomic_t enable_cnt; /* pci_enable_device has been called */
