USB: ehci-dbgp: stability improvements and external re-init
This patch implements several changes: 1) Improve the capability to debug the dbgp driver The dbgp_ehci_status() was added in a number of places to report the critical ehci registers to diagnose the cause of a failure of the ehci-dbgp driver. 2) Capability to survive the host controller initialization The dbgp_external_startup(), dbgp_not_safe, and dbgp_phys_port were added so as to allow the ehci-dbgp to re-initialize after the ehci host controller is reset by the standard host controller driver. This same routine is common for the early startup or re-initialization. This resulted in the need to move some of the initialization code out of the __init section because the ehci driver has the possibility to be loaded later on as a kernel module. 3) Stability improvements for device initialization The device enumeration from 0 to 127 has the possibility to fail the first time after a warm reset on some older EHCI debug controllers. The enumeration will be tried up to 3 times to account for this failure case. The dbg_wait_until_complete() was changed to wait up to 250 ms before failing which only comes into play during device initialization. The maximum delay will never get hit during the course of normal operation of the driver, unless the device got unplugged or there was a ehci controller failure, in which case the dbgp device driver will shut itself down. 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>
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