Messages in this thread | | | Date | Tue, 7 Jun 2016 18:23:01 +0200 | From | Alexandre Belloni <> | Subject | Re: [PATCH] ARM: at91: debug: use DEBUG_UART_VIRT |
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On 07/06/2016 at 17:48:21 +0200, Nicolas Ferre wrote : > Le 07/06/2016 17:24, Alexandre Belloni a écrit : > > AT91 still uses an offset (0x0100 0000) from the physical address to map > > the debug UART. This is unfortunate as for some platforms (sama5d3 and > > earlier), it ends up in the PCI zone and PCI is enabled in multi_v7. > > Switch to DEBUG_UART_VIRT to solve that. > > > > Tested on sama5d3 and 9g20. > > > > Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> > > People using their old defconfigs must pay attention to this change... > but it's true that it's a debug configuration anyway... >
I really doubt people are letting DEBUG_LL enabled in a production kernel...
> > diff --git a/arch/arm/include/debug/at91.S b/arch/arm/include/debug/at91.S > > index d4ae3b8e2426..0098401e5aeb 100644 > > --- a/arch/arm/include/debug/at91.S > > +++ b/arch/arm/include/debug/at91.S > > @@ -9,14 +9,6 @@ > > * > > */ > > > > -#ifdef CONFIG_MMU > > -#define AT91_IO_P2V(x) ((x) - 0x01000000) > > -#else > > -#define AT91_IO_P2V(x) (x) > > -#endif > > - > > -#define AT91_DEBUG_UART_VIRT AT91_IO_P2V(CONFIG_DEBUG_UART_PHYS) > > - > > #define AT91_DBGU_SR (0x14) /* Status Register */ > > #define AT91_DBGU_THR (0x1c) /* Transmitter Holding Register */ > > #define AT91_DBGU_TXRDY (1 << 1) /* Transmitter Ready */ > > @@ -24,7 +16,7 @@ > > > > .macro addruart, rp, rv, tmp > > ldr \rp, =CONFIG_DEBUG_UART_PHYS @ System peripherals (phys address) > > - ldr \rv, =AT91_DEBUG_UART_VIRT @ System peripherals (virt address) > > + ldr \rv, =CONFIG_DEBUG_UART_VIRT @ System peripherals (virt address) > > Shouldn't we protect the use of this defined value with some > #warning "Beware the value CONFIG_DEBUG_UART_VIRT haven't been defined: > is it intentional" > or even #error? > > or something like that? >
Well, those that are using this feature are supposed to know what they are doing. There is now protection for CONFIG_DEBUG_UART_PHYS anyway.
-- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com
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