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path: root/drivers/usb/early
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2010-05-20echi-dbgp: Add kernel debugger support for the usb debug portJason Wessel
This patch adds the capability to use the usb debug port with the kernel debugger. It is also still possible to use this functionality with or without the earlyprintk=dbgpX. It is possible to use the kgdbwait boot argument to debug very early in the kernel start up code. There are two ways to use this driver extension with a kernel boot argument. 1) kgdbdbgp=# -- Where # is the number of the usb debug controller You must use sysrq-g to break into the kernel debugger on another connection type other than the dbgp. 2) kgdbdbgp=#debugControlNum#,#Seconds# In this mode, the usb debug port is polled every #Seconds# for character input. It is possible to use gdb or press control-c to break into the kernel debugger. From the implementation perspective there are 3 high level changes. 1) Allow variable retries for the the hardware via dbgp_bulk_read(). The amount of retries for the dbgp_bulk_read() needed to be variable instead of fixed. We do not want to poll at all when the kernel is operating in interrupt driven mode. The polling only occurs if the kernel was booted when specifying some number of seconds via the kgdbdbgp boot argument (IE kgdbdbgp=0,1). In this case the loop count is reduced to 1 so as introduce the smallest amount of latency as possible. 2) Save the bulk IN endpoint address for use by the kgdb code. 3) The addition of the kgdb interface code. This consisted of adding in a character read function for the dbgp as well as a polling thread to allow the dbgp to interrupt the kernel execution. The rest is the typical kgdb I/O api. CC: Eric Biederman <ebiederm@xmission.com> CC: Yinghai Lu <yhlu.kernel@gmail.com> CC: linux-usb@vger.kernel.org Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-02USB: ehci-dbgp: split PID register updates for IN and OUT pipesJason Wessel
This patch addresses two problems: 1) Bulk reads should always use the DATA0 for the pid, and the write PID should toggle between DATA0 and DATA1. The fix is using dbgp_pid_write_update() and dbgp_pid_read_update(). 2) The delay loop for waiting for a transaction was not long enough to always complete the initial handshake inside dbgp_wait_until_done(). After the initial handshake the maximum delay length is never reached. The combined result of these two changes allows for the removal of the forced resynchronization where a bulk write was issued with a dummy data payload only to get the device to start accepting data writes again. CC: Eric Biederman <ebiederm@xmission.com> CC: Yinghai Lu <yhlu.kernel@gmail.com> Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-12-23USB: fix section mismatch in early ehci dbgpJan Beulich
Commit 917778267fbe67703ab7d5c6f0b7a05d4c3df485 removed __init from ehci_wait_for_port(), but left it in place on ehci_reset_port(), which is being called from the former function. Signed-off-by: Jan Beulich <jbeulich@novell.com> Acked-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: ehci-dbgp: errata for EHCI debug/host controller synchronizationJason Wessel
On some EHCI debug controllers after the host controller driver is activated, the debug controller will occasionally fail to submit a bulk write URB. On controllers that exhibit this behavior a dummy bulk write must get submitted to resynchronize the device. The "dummy bulk write" does not get received by the host attached to the other end of the usb debug device. The usb debug device simply acknowledges the "dummy bulk write" and returns to a usable state. The behavior, without this patch is that you see missing text from a complete kernel boot when using the keep option to the earlyprintk kernel argument. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: ehci-dbgp: errata for EHCI debug controller initializationJason Wessel
On some EHCI usb debug controllers, the EHCI debug device will fail to be seen after a port reset, after a warm reset. Two options exist to get the device to initialize correctly. Option 1 is to unplug and plug in the device. Option 2 is to use the EHCI port test to get the usb debug device to start talking again. At that point the debug controller port reset will succeed. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> CC: dbrownell@users.sourceforge.net Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: ehci-dbgp,ehci: Allow early or late use of the dbgp deviceJason Wessel
If the EHCI debug port is initialized and in use, the EHCI host controller driver must follow two rules. 1) If the EHCI host driver issues a controller reset, the debug controller driver re-initialization must get called after the reset is completed. 2) The EHCI host driver should ignore any requests to the physical EHCI debug port when the EHCI debug port is in use. The code to check for the debug port was moved from ehci_pci_reinit() to ehci_pci_setup because it must get called prior to ehci_reset() which will clear the debug port registers. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: dbrownell@users.sourceforge.net Cc: Ingo Molnar <mingo@elte.hu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: ehci-dbgp: stability improvements and external re-initJason Wessel
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>
2009-09-23USB: dbgp: EHCI debug controller initialization delaysJason Wessel
When using the EHCI host controller as a polled device, a bit more tolerance is required in terms of delays. On some 3+ghz systems the cpu loops were faster than the EHCI device mmio and resulted in the controller failing to initialize. On at least one first generation EHCI controller when it was not operating in interrupt mode, it would fail to report a port change status, but executing the port reset allowed the debug controller to work correctly anyway. This errata causes a one time 300ms delay in the boot time, where as the typical delay is 1-5ms for an EHCI controller that does not have this errata. The debug printk's were fixed to have the correct state messages, and there was a conversion from using early_printk to printk to avoid calling the dbgp driver while debugging the initialization. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: ehci-dbgp: Execute early BIOS hand offJason Wessel
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>
2009-09-23USB: dbgp: insert cr prior to nl as neededJason Wessel
The rs232 drivers send a carriage return prior to a new line in the early printk code. The usb debug driver should do the same because you want to be able to use the same terminal programs and tools for analysis of early printk data. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-23USB: ehci,dbgp,early_printk: split ehci debug driver from early_printk.cJason Wessel
Move the dbgp early printk driver in advance of refactoring and adding new code, so the changes to this code are tracked separately from the move of the code. The drivers/usb/early directory will be the location of the current and future early usb code for driving usb devices prior initializing the standard interrupt driven USB drivers. Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Yinghai Lu <yinghai@kernel.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>