On Friday 29 January 2016 09:01:31 Geert Uytterhoeven wrote:
> Hi Arnd,
>
> On Fri, Jan 29, 2016 at 12:07 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote:
> > The other related issue is the DEBUG_UART_{VIRT,PHYS} setting,
> > where there is no safe platform-specific default. I have two
> > ideas for working around that, maybe one of them sounds ok to
> > you:
> >
> > a) find a way to warn and/or disable DEBUG_LL when no address
> > is set, rather than failing the build
> >
> > b) add 'default 0 if COMPILE_TEST' to make it harder to get this
> > wrong by accident (hopefully nobody tries to run a COMPILE_TEST
> > kernel). Also maybe add a #warning if DEBUG_UART_VIRT is
>
> Make sure to add it at the end of the list, so enabling COMPILE_TEST in a
> working .config should give another working .config.
Sure, I've just done a largish series of patches in 4.5 to fix that
bug where we had it already.
> Perhaps you can use 0xdeadbeef instead of 0, and add
>
> #if DEBUG_UART_PHYS == 0xdeadbeed
> #warning Broken value of DEBUG_UART_PHYS.
> #endif
>
> somewhere?
I can do that, though I don't see much of an advantage, as zero
is no more likely to be a real address than 0xdeadbeed.
How about the version below?
Arnd
diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index c6b6175d0203..6cc09cf8618f 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -1526,6 +1526,7 @@ config DEBUG_UART_PHYS
default 0xfffb9800 if DEBUG_OMAP1UART3 || DEBUG_OMAP7XXUART3
default 0xfffe8600 if DEBUG_BCM63XX_UART
default 0xfffff700 if ARCH_IOP33X
+ default 0xdeadbeef if DEBUG_LL_UART_8250 || DEBUG_LL_UART_PL01X || DEBUG_LL_UART_EFM32
depends on ARCH_EP93XX || \
DEBUG_LL_UART_8250 || DEBUG_LL_UART_PL01X || \
DEBUG_LL_UART_EFM32 || \
@@ -1628,6 +1629,7 @@ config DEBUG_UART_VIRT
default 0xff003000 if DEBUG_U300_UART
default 0xffd01000 if DEBUG_HIP01_UART
default DEBUG_UART_PHYS if !MMU
+ default 0xdeadbeef if DEBUG_LL_UART_8250 || DEBUG_LL_UART_PL01X || DEBUG_LL_UART_EFM32
depends on DEBUG_LL_UART_8250 || DEBUG_LL_UART_PL01X || \
DEBUG_UART_8250 || DEBUG_UART_PL01X || DEBUG_MESON_UARTAO || \
DEBUG_NETX_UART || \
diff --git a/arch/arm/include/debug/8250.S b/arch/arm/include/debug/8250.S
index 7f7446f6f806..1191b1458586 100644
--- a/arch/arm/include/debug/8250.S
+++ b/arch/arm/include/debug/8250.S
@@ -9,6 +9,9 @@
*/
#include <linux/serial_reg.h>
+#if CONFIG_DEBUG_UART_PHYS == 0xdeadbeef || CONFIG_DEBUG_UART_VIRT < 0xe0000000
+#include "none.S"
+#else
.macro addruart, rp, rv, tmp
ldr \rp, =CONFIG_DEBUG_UART_PHYS
ldr \rv, =CONFIG_DEBUG_UART_VIRT
@@ -55,3 +58,5 @@
beq 1001b
#endif
.endm
+
+#endif
diff --git a/arch/arm/include/debug/efm32.S b/arch/arm/include/debug/efm32.S
index 660fa1e4b77b..537021761e4a 100644
--- a/arch/arm/include/debug/efm32.S
+++ b/arch/arm/include/debug/efm32.S
@@ -6,6 +6,9 @@
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
+#if CONFIG_DEBUG_UART_PHYS == 0xdeadbeef || CONFIG_DEBUG_UART_VIRT < 0xf0000000
+#include "none.S"
+#else
#define UARTn_CMD 0x000c
#define UARTn_CMD_TXEN 0x0004
@@ -43,3 +46,5 @@
tst \rd, #UARTn_STATUS_TXC
bne 1001b
.endm
+
+#endif
diff --git a/arch/arm/include/debug/none.S b/arch/arm/include/debug/none.S
new file mode 100644
index 000000000000..75cd1bbee5c4
--- /dev/null
+++ b/arch/arm/include/debug/none.S
@@ -0,0 +1,16 @@
+
+#warning DEBUG_LL not configured, disabling
+
+ .macro addruart, rp, rv, tmp
+ ldr \rp, =0
+ ldr \rv, =0
+ .endm
+
+ .macro senduart,rd,rx
+ .endm
+
+ .macro busyuart,rd,rx
+ .endm
+
+ .macro waituart,rd,rx
+ .endm
diff --git a/arch/arm/include/debug/pl01x.S b/arch/arm/include/debug/pl01x.S
index f7d8323cefcc..fbe0cad32be0 100644
--- a/arch/arm/include/debug/pl01x.S
+++ b/arch/arm/include/debug/pl01x.S
@@ -10,6 +10,9 @@
* published by the Free Software Foundation.
*
*/
+#if CONFIG_DEBUG_UART_PHYS == 0xdeadbeef || CONFIG_DEBUG_UART_VIRT < 0xf0000000
+#include "none.S"
+#else
#include <linux/amba/serial.h>
#ifdef CONFIG_DEBUG_ZTE_ZX
@@ -43,3 +46,4 @@
tst \rd, #UART01x_FR_BUSY
bne 1001b
.endm
+#endif
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