Re: [PATCH] OMAP: config : disable the usb host configuration in omap2plus_defconfig

[Kevin Hilman <khilman@ti.com>]

Keshava Munegowda <keshava_mgowda@ti.com> writes:

> The usb host is disabled in the omap2 build; This is because
> usb host is causing the retention to break in cpu idle.

... and causes warnings during boot, and hangs in suspend, can't suspend
using NFSroot, etc. etc.

Thank you for disabling this by default, But I don't think this fix
is targetted enough (more below.)

Tony, when v3.5 came out, I asked them to fix this properly, but nothing
was done.  So I've resorted to requesting that this feature be disabled
by default since it introduced PM regressions.  Of course, I'd like to
see this fixed properly instead, but we've run out of time for v3.5 and
IMO, this PM regression needs to be fixed for v3.5.  See my more
targetted patches below.

> Signed-off-by: Keshava Munegowda <keshava_mgowda@ti.com>
> ---
>  arch/arm/configs/omap2plus_defconfig |   11 -----------
>  1 file changed, 11 deletions(-)
>
> diff --git a/arch/arm/configs/omap2plus_defconfig b/arch/arm/configs/omap2plus_defconfig
> index 9854ff4..7b32da6 100644
> --- a/arch/arm/configs/omap2plus_defconfig
> +++ b/arch/arm/configs/omap2plus_defconfig
> @@ -170,17 +170,6 @@ CONFIG_SND_USB_AUDIO=m
>  CONFIG_SND_SOC=m
>  CONFIG_SND_OMAP_SOC=m
>  CONFIG_SND_OMAP_SOC_OMAP3_PANDORA=m
> -CONFIG_USB=y
> -CONFIG_USB_DEBUG=y
> -CONFIG_USB_ANNOUNCE_NEW_DEVICES=y
> -CONFIG_USB_DEVICEFS=y
> -CONFIG_USB_SUSPEND=y
> -CONFIG_USB_MON=y
> -CONFIG_USB_EHCI_HCD=y
> -CONFIG_USB_WDM=y
> -CONFIG_USB_STORAGE=y
> -CONFIG_USB_LIBUSUAL=y
> -CONFIG_USB_TEST=y

Why disable all of these?  With that, it's not terribly clear what is
going on, or why.

Instead, what you need is a targetted fix to just disable the problem
driver by default:

Either this:

diff --git a/arch/arm/configs/omap2plus_defconfig b/arch/arm/configs/omap2plus_defconfig
index 9854ff4..11828e6 100644
--- a/arch/arm/configs/omap2plus_defconfig
+++ b/arch/arm/configs/omap2plus_defconfig
@@ -176,7 +176,6 @@ CONFIG_USB_ANNOUNCE_NEW_DEVICES=y
 CONFIG_USB_DEVICEFS=y
 CONFIG_USB_SUSPEND=y
 CONFIG_USB_MON=y
-CONFIG_USB_EHCI_HCD=y
 CONFIG_USB_WDM=y
 CONFIG_USB_STORAGE=y
 CONFIG_USB_LIBUSUAL=y

or this:

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index e129c82..3747826 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -825,7 +825,7 @@ config MFD_WL1273_CORE
 config MFD_OMAP_USB_HOST
 	bool "Support OMAP USBHS core driver"
 	depends on USB_EHCI_HCD_OMAP || USB_OHCI_HCD_OMAP3
-	default y
+	default n
 	help
 	  This is the core driver for the OAMP EHCI and OHCI drivers.
 	  This MFD driver does the required setup functionalities for

Will have the inteded affect with the benefit of being much clearer
about what is actually being disabled, and why.

Kevin