On 05/09/2011 09:24 AM, Greg KH wrote:
> At worse
> case, could we trigger off of known DMI strings for the broken machines?
This works. Does it look like something you would take?
It's probably best to wait a day though: I'm waiting for feedback from WeTab users (same hardware, slightly different
BIOS) to see if they're affected and what their DMI values are.
Andy
>From 2bad65bc37d4a027ba1df961926dfb09e465f0b5 Mon Sep 17 00:00:00 2001
From: Andy Ross <andy.ross@xxxxxxxxxxxxx>
Date: Mon, 9 May 2011 11:39:17 -0700
Subject: [PATCH] ehci: Fix boot hang in BIOS handoff on ExoPC
The Pegatron Lucid tablets sporadically hang for 90+ seconds on boot
trying to do the EHCI BIOS handoff. Skip negotiation for those
devices and force the handoff.
Signed-off-by: Andy Ross <andy.ross@xxxxxxxxxxxxx>
---
drivers/usb/host/pci-quirks.c | 21 +++++++++++++++++----
1 files changed, 17 insertions(+), 4 deletions(-)
diff --git a/drivers/usb/host/pci-quirks.c b/drivers/usb/host/pci-quirks.c
index 4c502c8..d7ada08 100644
--- a/drivers/usb/host/pci-quirks.c
+++ b/drivers/usb/host/pci-quirks.c
@@ -14,6 +14,7 @@
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/acpi.h>
+#include <linux/dmi.h>
#include "pci-quirks.h"
#include "xhci-ext-caps.h"
@@ -222,6 +223,7 @@ static void __devinit quirk_usb_disable_ehci(struct pci_dev *pdev)
u8 offset, cap_length;
int count = 256/4;
int tried_handoff = 0;
+ int force_handoff = 0;
if (!mmio_resource_enabled(pdev, 0))
return;
@@ -233,6 +235,12 @@ static void __devinit quirk_usb_disable_ehci(struct pci_dev *pdev)
cap_length = readb(base);
op_reg_base = base + cap_length;
+ /* The Pegatron Lucid (ExoPC) tablet sporadically waits for 90
+ * seconds trying the handoff. Skip it. */
+ if (!strcmp(dmi_get_system_info(DMI_BOARD_NAME), "EXOPG06411") &&
+ !strcmp(dmi_get_system_info(DMI_BIOS_VERSION), "Lucid-CE-133"))
+ force_handoff = 1;
+
/* EHCI 0.96 and later may have "extended capabilities"
* spec section 5.1 explains the bios handoff, e.g. for
* booting from USB disk or using a usb keyboard
@@ -270,14 +278,17 @@ static void __devinit quirk_usb_disable_ehci(struct pci_dev *pdev)
* set for any other reason than forcing a BIOS
* handoff..
*/
- pci_write_config_byte(pdev, offset + 3, 1);
+ if (!force_handoff)
+ pci_write_config_byte(pdev,
+ offset + 3, 1);
}
/* if boot firmware now owns EHCI, spin till
* it hands it over.
*/
msec = 1000;
- while ((cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
+ while (!force_handoff &&
+ (cap & EHCI_USBLEGSUP_BIOS) && (msec > 0)) {
tried_handoff = 1;
msleep(10);
msec -= 10;
@@ -288,8 +299,10 @@ static void __devinit quirk_usb_disable_ehci(struct pci_dev *pdev)
/* well, possibly buggy BIOS... try to shut
* it down, and hope nothing goes too wrong
*/
- dev_warn(&pdev->dev, "EHCI: BIOS handoff failed"
- " (BIOS bug?) %08x\n", cap);
+ if (!force_handoff)
+ dev_warn(&pdev->dev,
+ "EHCI: BIOS handoff failed"
+ " (BIOS bug?) %08x\n", cap);
pci_write_config_byte(pdev, offset + 2, 0);
}
--
1.7.1
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