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| author | Jason Wessel <jason.wessel@windriver.com> | 2009-08-20 15:39:50 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2009-09-23 06:46:38 -0700 |
| commit | 093344e1362cbf9525a5da09a565f357d8102f3b (patch) | |
| tree | b5e7fe63e9a69799c73e25a37e58d69be331463c /drivers/usb | |
| parent | 87a5d15154ae2389251e6ad99216a846b905375c (diff) | |
| download | linux-093344e1362cbf9525a5da09a565f357d8102f3b.tar.gz linux-093344e1362cbf9525a5da09a565f357d8102f3b.tar.bz2 linux-093344e1362cbf9525a5da09a565f357d8102f3b.zip | |
USB: ehci-dbgp: Execute early BIOS hand off
The PCI quirk code executes a BIOS hand off to obtain full control of
the EHCI host controller, the self contained ehci-dbgp driver must do
the same thing using the early PCI API, else the BIOS can cause a
fatal fault.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: dbrownell@users.sourceforge.net
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb')
| -rw-r--r-- | drivers/usb/early/ehci-dbgp.c | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/drivers/usb/early/ehci-dbgp.c b/drivers/usb/early/ehci-dbgp.c index 8de709ac0f55..7deae97fe50f 100644 --- a/drivers/usb/early/ehci-dbgp.c +++ b/drivers/usb/early/ehci-dbgp.c @@ -435,6 +435,53 @@ static void __init detect_set_debug_port(void) } } +/* The code in early_ehci_bios_handoff() is derived from the usb pci + * quirk initialization, but altered so as to use the early PCI + * routines. */ +#define EHCI_USBLEGSUP_BIOS (1 << 16) /* BIOS semaphore */ +#define EHCI_USBLEGCTLSTS 4 /* legacy control/status */ +static void __init early_ehci_bios_handoff(void) +{ + u32 hcc_params = readl(&ehci_caps->hcc_params); + int offset = (hcc_params >> 8) & 0xff; + u32 cap; + int msec; + + if (!offset) + return; + + cap = read_pci_config(ehci_dev.bus, ehci_dev.slot, + ehci_dev.func, offset); + dbgp_printk("dbgp: ehci BIOS state %08x\n", cap); + + if ((cap & 0xff) == 1 && (cap & EHCI_USBLEGSUP_BIOS)) { + dbgp_printk("dbgp: BIOS handoff\n"); + write_pci_config_byte(ehci_dev.bus, ehci_dev.slot, + ehci_dev.func, offset + 3, 1); + } + + /* if boot firmware now owns EHCI, spin till it hands it over. */ + msec = 1000; + while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) { + mdelay(10); + msec -= 10; + cap = read_pci_config(ehci_dev.bus, ehci_dev.slot, + ehci_dev.func, offset); + } + + if (cap & EHCI_USBLEGSUP_BIOS) { + /* well, possibly buggy BIOS... try to shut it down, + * and hope nothing goes too wrong */ + dbgp_printk("dbgp: BIOS handoff failed: %08x\n", cap); + write_pci_config_byte(ehci_dev.bus, ehci_dev.slot, + ehci_dev.func, offset + 2, 0); + } + + /* just in case, always disable EHCI SMIs */ + write_pci_config_byte(ehci_dev.bus, ehci_dev.slot, ehci_dev.func, + offset + EHCI_USBLEGCTLSTS, 0); +} + static int __init ehci_setup(void) { struct usb_debug_descriptor dbgp_desc; @@ -446,6 +493,8 @@ static int __init ehci_setup(void) int port_map_tried; int playtimes = 3; + early_ehci_bios_handoff(); + try_next_time: port_map_tried = 0; |