Re: [PATCH] Don't touch USB controllers with MMIO disabled in quirks

From: Linus Torvalds
Date: Mon Oct 31 2005 - 23:34:46 EST




On Tue, 1 Nov 2005, Paul Mackerras wrote:
>
> I still think that a FIXUP_HEADER header is the wrong place to be
> doing this sort of thing, and that code that touches a device without
> doing pci_enable_device is just asking for trouble; however, in order
> to get my machine to be able to boot, this patch adds a check that
> MMIO is enabled for the device, and if it isn't, leaves the device
> alone. With this patch my powerbook will boot.

Well, this can't be right, because depending on which controller type it
is, the handoff code uses PIO, not MMIO. In fact, a uhci controller
wouldn't necessarily ever have PCI_COMMAND_MEMORY set afaik, since it
doesn't even _have_ MMIO.

Would something like the appended work instead?

Linus

---
diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index b7fd3f6..b1aa350 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -138,11 +138,23 @@ reset_needed:
}
EXPORT_SYMBOL_GPL(uhci_check_and_reset_hc);

+static inline int io_type_enabled(struct pci_dev *pdev, unsigned int mask)
+{
+ u16 cmd;
+ return !pci_read_config_word(pdev, PCI_COMMAND, &cmd) && (cmd & mask);
+}
+
+#define pio_enabled(dev) io_type_enabled(dev, PCI_COMMAND_IO)
+#define mmio_enabled(dev) io_type_enabled(dev, PCI_COMMAND_MEMORY)
+
static void __devinit quirk_usb_handoff_uhci(struct pci_dev *pdev)
{
unsigned long base = 0;
int i;

+ if (!pio_enabled(pdev))
+ return;
+
for (i = 0; i < PCI_ROM_RESOURCE; i++)
if ((pci_resource_flags(pdev, i) & IORESOURCE_IO)) {
base = pci_resource_start(pdev, i);
@@ -153,12 +165,20 @@ static void __devinit quirk_usb_handoff_
uhci_check_and_reset_hc(pdev, base);
}

+static int __devinit mmio_resource_enabled(struct pci_dev *pdev, int idx)
+{
+ return pci_resource_start(pdev, idx) && mmio_enabled(pdev);
+}
+
static void __devinit quirk_usb_handoff_ohci(struct pci_dev *pdev)
{
void __iomem *base;
int wait_time;
u32 control;

+ if (!mmio_resource_enabled(pdev, 0))
+ return;
+
base = ioremap_nocache(pci_resource_start(pdev, 0),
pci_resource_len(pdev, 0));
if (base == NULL) return;
@@ -201,6 +221,9 @@ static void __devinit quirk_usb_disable_
u32 hcc_params, val, temp;
u8 cap_length;

+ if (!mmio_resource_enabled(pdev, 0))
+ return;
+
base = ioremap_nocache(pci_resource_start(pdev, 0),
pci_resource_len(pdev, 0));
if (base == NULL) return;
-
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