: Add command-line option to i8042 to completely disable it
Subsystems (2)
PATCH 1/1 : Add command-line option to i8042 to completely disable it
(I tried to send this patch to linux-input@, but it seems to be currently having some problems, so I'm going directly to LKML).
Certain (broken) pieces of South Bridge hardware will respond to i8042_read_status() on boot with 0x0, despite there not being a real i8042 controller hooked up in the south bridge. This can cause the detection for the i8042 to return a "phantom" device, which hangs up later initialization. Note that using "i8042.nokbd" and/or "i8042.noaux" do not help with this, since this shows up during i8042_controller_check() (before either of those options are checked). This patch adds a command-line option "i8042.disable", which just completely disables any checking for the i8042 controller.
drivers/input/serio/i8042.c +9 -0
@@ -27,6 +27,10 @@ MODULE_AUTHOR("Vojtech Pavlik <[email protected]>");MODULE_DESCRIPTION ("i8042 keyboard and mouse controller driver" );MODULE_LICENSE ("GPL" ); +static unsigned int i8042_disable; +module_param_named (disable, i8042_disable, bool,0 ); +MODULE_PARM_DESC (disable,"Do not probe i8042 at all." ); +static unsigned int i8042_nokbd;module_param_named (nokbd, i8042_nokbd, bool,0 );MODULE_PARM_DESC (nokbd,"Do not probe or use KBD port." );
@@ -1194,6 +1198,11 @@ static int __init i8042_init(void) {int err; +if (i8042_disable) { +printk (KERN_ERR "i8042.c: Controller disabled by kernel command-line\n" ); +return -ENODEV ; + } +dbg_init (); err =i8042_platform_init ();
Quoted 11 lines · On Mon, 23 Jul 2007 13:05:22 -0400 Chris Lalancette <[email protected]> wrote:
(I tried to send this patch to linux-input@, but it seems to be currently having some problems, so I'm going directly to LKML).
Certain (broken) pieces of South Bridge hardware will respond to
i8042_read_status()on boot with0x0, despite there not being a real i8042 controller hooked up in the south bridge. This can cause the detection for the i8042 to return a "phantom" device, which hangs up later initialization. Note that using "i8042.nokbd" and/or "i8042.noaux" do not help with this, since this shows up duringi8042_controller_check()(before either of those options are checked). This patch adds a command-line option "i8042.disable", which just completely disables any checking for the i8042 controller.
That's an unfortunate fix. Is there really no way in which we can auto-detect such a situation without requiring a manual setting?
Quoted 14 lines · Andrew Morton
Quoted 11 lines · On Mon, 23 Jul 2007 13:05:22 -0400 Chris Lalancette <[email protected]> wrote:
(I tried to send this patch to linux-input@, but it seems to be currently having some problems, so I'm going directly to LKML).
Certain (broken) pieces of South Bridge hardware will respond to
i8042_read_status()on boot with0x0, despite there not being a real i8042 controller hooked up in the south bridge. This can cause the detection for the i8042 to return a "phantom" device, which hangs up later initialization. Note that using "i8042.nokbd" and/or "i8042.noaux" do not help with this, since this shows up duringi8042_controller_check()(before either of those options are checked). This patch adds a command-line option "i8042.disable", which just completely disables any checking for the i8042 controller.
Quoted 3 lines
That's an unfortunate fix. Is there really no way in which we can auto-detect such a situation without requiring a manual setting?
The fact that the current detection hangs suggests that the scenario is possible to detect.
Signature · 2 lines
Vojtech Pavlik Director SuSE Labs
Quoted 9 lines · Vojtech Pavlik
Quoted 4 lines
That's an unfortunate fix. Is there really no way in which we can auto-detect such a situation without requiring a manual setting?
The fact that the current detection hangs suggests that the scenario is possible to detect.
Hm, OK. I'll go back and look at i8042_flush() to see if I can detect this erroneous situation automatically and fail the i8042_controller_init() if I see it.
Chris Lalancette