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authorLinus Walleij <linus.walleij@linaro.org>2020-08-27 23:28:56 +0100
committerRussell King <rmk+kernel@armlinux.org.uk>2020-09-15 14:35:28 +0100
commit4df24fef09615d8f7dd2120f5072486addfd3eb9 (patch)
tree83a392d879ccb5dc6556ce3e6595b43b38dba597 /arch/arm/kernel/debug.S
parent2c50a570e9dc649c182268e779dffe0712e98a6a (diff)
ARM: 9005/1: debug: Select flow control for all debug UARTs
Instead of a flow control selection mechanism specifically for 8250, make this available for all debug UARTs. If the debug UART supports waiting for CTS to be asserted, then this code can be activated for terminals that need it. We keep the defaults for EBSA110, Footbridge, Gemini and RPC so that this still works as expected for these older platforms: they assume that flow control shall be enabled for debug prints. I switch the location of the check for ifdef CONFIG_DEBUG_UART_FLOW_CONTROL from the actual debug UART drivers: the code would get compiled-out for 8250 and Tegra unless their custom config (or passing -DFLOW_CONTROL in the Tegra case) was not set. Instead this is conditional at the three places where we print debug messages. The idea is that debug UARTs can be implemented without this ifdef boilerplate so they look cleaner, alas the ifdef has to be somewhere. Signed-off-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Diffstat (limited to 'arch/arm/kernel/debug.S')
-rw-r--r--arch/arm/kernel/debug.S7
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/arm/kernel/debug.S b/arch/arm/kernel/debug.S
index e7c87522c176..d92f44bdf438 100644
--- a/arch/arm/kernel/debug.S
+++ b/arch/arm/kernel/debug.S
@@ -89,12 +89,17 @@ ENTRY(printascii)
2: teq r1, #'\n'
bne 3f
mov r1, #'\r'
+#ifdef CONFIG_DEBUG_UART_FLOW_CONTROL
waituartcts r2, r3
+#endif
waituarttxrdy r2, r3
senduart r1, r3
busyuart r2, r3
mov r1, #'\n'
-3: waituartcts r2, r3
+3:
+#ifdef CONFIG_DEBUG_UART_FLOW_CONTROL
+ waituartcts r2, r3
+#endif
waituarttxrdy r2, r3
senduart r1, r3
busyuart r2, r3