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path: root/arch/powerpc/kernel/udbg_16550.c
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2009-03-11powerpc/udbg: Fix lost byte during console handover; change LFCR to CRLFAndrew Klossner
When the console is on a serial port to be driven by serial8250, a character can be lost from the end of the first line in the two-line sequence serial8250.0: ttyS0 at MMIO 0xe0004500 (irq = 42) is a 16550A console handover: boot [udbg0] -> real [ttyS0] This happens because udbg_puts or udbg_write stuff the last byte of the line into the Tx FIFO and return, whereupon the serial8250 initialization code immediately empties that FIFO. The fix: udbg_puts and udbg_write now wait for the Tx FIFO to clear before returning. This delays the system by one additional serial frame time for each line written by udbg, but the effect is not noticeable, a cumulative 17 milliseconds for 200 lines of early printk output at 115200 baud. Also, the routines in udbg_16550.c now emit CRLF instead of LFCR. Linux makes a point of emitting CRLF because, when serial output is captured to a file, LFCR sequences can confuse text editors. See http://lkml.org/lkml/2006/2/4/50 for some history. Signed-off-by: Andrew Klossner <andrew@cesa.opbu.xerox.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2008-10-21powerpc: Unsigned speed cannot be negative in udbg_16559.croel kluin
"unsigned int" speed cannot be negative, it's thus pointless to test if it is. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2007-12-23[POWERPC] 4xx: Add early udbg support for 40x processorsBenjamin Herrenschmidt
This adds some basic real mode based early udbg support for 40x in order to debug things more easily Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
2007-12-11[POWERPC] Remove useless volatiles in udbg_16550.cBenjamin Herrenschmidt
This removes "volatile" from the MMIO pointer udbg_comport in udbg_16550.c driver, it's useless and makes checkpatch.pl complain when adding things to this file. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-09-19[POWERPC] 4xx: Implement udbg_getc() for 440Hollis Blanchard
Implement udbg_getc() for 440, which fixes xmon input. Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com> Acked-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
2007-05-08[POWERPC] Early serial debug support for PPC44xDavid Gibson
This adds support for early serial debugging via the built in port on IBM/AMCC PowerPC 44x CPUs. It uses a bolted TLB entry in address space 1 for the UART's mapping, allowing robust debugging both before and after the initialization of the MMU. Signed-off-by: David Gibson <dwg@au1.ibm.com> Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-03-14[PATCH] constant should be longAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Olof Johansson <olof@lixom.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-02-07[POWERPC] pasemi: UART udbg supportOlof Johansson
Early debug output for PA Semi UART. Uses the 2.05 CI real mode ops. Signed-off-by: Olof Johansson <olof@lixom.net> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-07-26[POWERPC] Fix default clock for udbg_16550Benjamin Herrenschmidt
This patch makes it possible to provide 0 as the clock value for udbg_16550, making it default to the standard 1.8432Mhz clock Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-06-30Remove obsolete #include <linux/config.h>Jörn Engel
Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-02-07[PATCH] powerpc: fix compile warning in udbg_init_maple_realmodeOlaf Hering
arch/powerpc/kernel/udbg_16550.c: In function `udbg_init_maple_realmode': arch/powerpc/kernel/udbg_16550.c:162: warning: assignment from incompatible pointer type Signed-off-by: Olaf Hering <olh@suse.de> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-11[PATCH] powerpc: Make early debugging configurable via KconfigMichael Ellerman
This patch adds Kconfig entries to control the early debugging options, currently in setup_64.c. Doing this via Kconfig rather than #defines means you can have one source tree, which is buildable for multiple platforms - and you can enable the correct early debug option for each platform via .config. I made udbg_early_init() a static inline because otherwise GCC is to daft to optimise it away when debugging is off. Now that we have udbg_init_rtas() we can make call_rtas_display_status* static. Signed-off-by: Michael Ellerman <michael@ellerman.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-09[PATCH] powerpc: Loosen udbg_probe_uart_speed sanity checkingKumar Gala
The checking of the baudrate in udbg_probe_uart_speed was too tight and would cause reporting back of the default baud rate in cases where the computed speed was valid. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-09[PATCH] powerpc: udbg updatesBenjamin Herrenschmidt
The udbg low level io layer has an issue with udbg_getc() returning a char (unsigned on ppc) instead of an int, thus the -1 if you had no available input device could end up turned into 0xff, filling your display with bogus characters. This fixes it, along with adding a little blob to xmon to do a delay before exiting when getting an EOF and fixing the detection of ADB keyboards in udbg_adb.c Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-09[PATCH] powerpc: Unify udbg (#2)Benjamin Herrenschmidt
This patch unifies udbg for both ppc32 and ppc64 when building the merged achitecture. xmon now has a single "back end". The powermac udbg stuff gets enriched with some ADB capabilities and btext output. In addition, the early_init callback is now called on ppc32 as well, approx. in the same order as ppc64 regarding device-tree manipulations. The init sequences of ppc32 and ppc64 are getting closer, I'll unify them in a later patch. For now, you can force udbg to the scc using "sccdbg" or to btext using "btextdbg" on powermacs. I'll implement a cleaner way of forcing udbg output to something else than the autodetected OF output device in a later patch. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2006-01-09[PATCH] powerpc: serial port discovery (#2)Benjamin Herrenschmidt
This moves the discovery of legacy serial ports to a separate file, makes it common to ppc32 and ppc64, and reworks it to use the new OF address translators to get to the ports early. This new version can also detect some PCI serial cards using legacy chips and will probably match those discovered port with the default console choice. Only ppc64 gets udbg still yet, unifying udbg isn't finished yet. It also adds some speed-probing code to udbg so that the default console can come up at the same speed it was set to by the firmware. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2005-11-11[PATCH] powerpc: Move udbg code to arch/powerpcDavid Gibson
Since the udbg code in ppc64 has no ppc32 equivalent, move it straight over into arch/powerpc (and include/asm-powerpc for udbg.h). In time, we probably want to meld the various bits and pieces of 32-bit early debugging code into udbg, but for now only include it on CONFIG_PPC64=y builds. The only change during the move is to standardise the protecting #ifdef/#define in udbg.h, and move its banner comment above the initial #ifdef (which seems to be normal practice). Built and booted on POWER5 LPAR (ARCH=powerpc and ARCH=ppc64). Built for 32bit multiplatform (ARCH=powerpc). Signed-off-by: David Gibson <david@gibson.dropbear.id.au> Signed-off-by: Paul Mackerras <paulus@samba.org>