| Message ID | 1369888827-9427-1-git-send-email-tushar.behera@linaro.org |
|---|---|
| State | New |
| Headers | show |
Hi, On Wed, May 29, 2013 at 9:40 PM, Tushar Behera <tushar.behera@linaro.org> wrote: > There are two definitions for low-level UART ports for Exynos platform. > CONFIG_S3C_LOWLEVEL_UART_PORT is used for printing "Uncompressing > Linux... done, booting the kernel." and CONFIG_S3C_UART for other > low-level messages. > > The assumption for both the uart ports is that they are pre-configured > in the bootloader. Since they are essentially the same always, it > would be good to consolidate them to use only one macro, in this case > 'DEBUG_S3C_UART' would be a better option. > > 'DEBUG_S3C_UART' is defined only if DEBUG_LL is enabled. We can safely > disable this option when DEBUG_LL is not defined and we can boot various > boards with different UART port settings. Only drawback of this > approach is that when DEBUG_LL is not defined, we would be missing the > print "Uncompressing Linux... done, booting the kernel." > > Since CONFIG_S3C_LOWLEVEL_UART_PORT is still used by other Samsung > boards, the consolidation applies only for ARCH_EXYNOS. > > Signed-off-by: Tushar Behera <tushar.behera@linaro.org> This looks reasonable, but you have to convert the other samsung platforms too -- it's not ok to ignore them. -Olof
On 05/31/2013 02:41 AM, Olof Johansson wrote: > Hi, > > On Wed, May 29, 2013 at 9:40 PM, Tushar Behera <tushar.behera@linaro.org> wrote: >> There are two definitions for low-level UART ports for Exynos platform. >> CONFIG_S3C_LOWLEVEL_UART_PORT is used for printing "Uncompressing >> Linux... done, booting the kernel." and CONFIG_S3C_UART for other >> low-level messages. >> >> The assumption for both the uart ports is that they are pre-configured >> in the bootloader. Since they are essentially the same always, it >> would be good to consolidate them to use only one macro, in this case >> 'DEBUG_S3C_UART' would be a better option. >> >> 'DEBUG_S3C_UART' is defined only if DEBUG_LL is enabled. We can safely >> disable this option when DEBUG_LL is not defined and we can boot various >> boards with different UART port settings. Only drawback of this >> approach is that when DEBUG_LL is not defined, we would be missing the >> print "Uncompressing Linux... done, booting the kernel." >> >> Since CONFIG_S3C_LOWLEVEL_UART_PORT is still used by other Samsung >> boards, the consolidation applies only for ARCH_EXYNOS. >> >> Signed-off-by: Tushar Behera <tushar.behera@linaro.org> > > This looks reasonable, but you have to convert the other samsung > platforms too -- it's not ok to ignore them. > Sure thing. I will update those platforms in a subsequent patchset. > > -Olof >
Tushar Behera <tushar.behera@linaro.org> writes: > There are two definitions for low-level UART ports for Exynos platform. > CONFIG_S3C_LOWLEVEL_UART_PORT is used for printing "Uncompressing > Linux... done, booting the kernel." and CONFIG_S3C_UART for other > low-level messages. > > The assumption for both the uart ports is that they are pre-configured > in the bootloader. Since they are essentially the same always, it > would be good to consolidate them to use only one macro, in this case > 'DEBUG_S3C_UART' would be a better option. > > 'DEBUG_S3C_UART' is defined only if DEBUG_LL is enabled. We can safely > disable this option when DEBUG_LL is not defined and we can boot various > boards with different UART port settings. Only drawback of this > approach is that when DEBUG_LL is not defined, we would be missing the > print "Uncompressing Linux... done, booting the kernel." Perfectly acceptable to me (and already the case on OMAP.) > Since CONFIG_S3C_LOWLEVEL_UART_PORT is still used by other Samsung > boards, the consolidation applies only for ARCH_EXYNOS. > > Signed-off-by: Tushar Behera <tushar.behera@linaro.org> Acked-by: Kevin Hilman <khilman@linaro.org>
On 05/31/2013 11:50 PM, Kevin Hilman wrote: > Tushar Behera <tushar.behera@linaro.org> writes: > >> There are two definitions for low-level UART ports for Exynos platform. >> CONFIG_S3C_LOWLEVEL_UART_PORT is used for printing "Uncompressing >> Linux... done, booting the kernel." and CONFIG_S3C_UART for other >> low-level messages. >> >> The assumption for both the uart ports is that they are pre-configured >> in the bootloader. Since they are essentially the same always, it >> would be good to consolidate them to use only one macro, in this case >> 'DEBUG_S3C_UART' would be a better option. >> >> 'DEBUG_S3C_UART' is defined only if DEBUG_LL is enabled. We can safely >> disable this option when DEBUG_LL is not defined and we can boot various >> boards with different UART port settings. Only drawback of this >> approach is that when DEBUG_LL is not defined, we would be missing the >> print "Uncompressing Linux... done, booting the kernel." > > Perfectly acceptable to me (and already the case on OMAP.) > >> Since CONFIG_S3C_LOWLEVEL_UART_PORT is still used by other Samsung >> boards, the consolidation applies only for ARCH_EXYNOS. >> >> Signed-off-by: Tushar Behera <tushar.behera@linaro.org> > > Acked-by: Kevin Hilman <khilman@linaro.org> > Thanks Kevin. I have an updated version of this patch updated for all of Samsung platforms.[1] [1] http://www.gossamer-threads.com/lists/linux/kernel/1723429
diff --git a/arch/arm/mach-exynos/include/mach/uncompress.h b/arch/arm/mach-exynos/include/mach/uncompress.h index 2979995..45b5c2a 100644 --- a/arch/arm/mach-exynos/include/mach/uncompress.h +++ b/arch/arm/mach-exynos/include/mach/uncompress.h @@ -37,11 +37,16 @@ static void arch_detect_cpu(void) chip_id >>= 20; chip_id &= 0xf; +#ifdef CONFIG_DEBUG_LL if (chip_id == 0x5) - uart_base = (volatile u8 *)EXYNOS5_PA_UART + (S3C_UART_OFFSET * CONFIG_S3C_LOWLEVEL_UART_PORT); + uart_base = (volatile u8 *)EXYNOS5_PA_UART + + (S3C_UART_OFFSET * CONFIG_DEBUG_S3C_UART); else - uart_base = (volatile u8 *)EXYNOS4_PA_UART + (S3C_UART_OFFSET * CONFIG_S3C_LOWLEVEL_UART_PORT); - + uart_base = (volatile u8 *)EXYNOS4_PA_UART + + (S3C_UART_OFFSET * CONFIG_DEBUG_S3C_UART); +#else + uart_base = 0; +#endif /* * For preventing FIFO overrun or infinite loop of UART console, * fifo_max should be the minimum fifo size of all of the UART channels diff --git a/arch/arm/plat-samsung/include/plat/uncompress.h b/arch/arm/plat-samsung/include/plat/uncompress.h index 438b248..028c2a8 100644 --- a/arch/arm/plat-samsung/include/plat/uncompress.h +++ b/arch/arm/plat-samsung/include/plat/uncompress.h @@ -38,7 +38,11 @@ static void arch_detect_cpu(void); #define FIFO_MAX (14) #ifdef S3C_PA_UART -#define uart_base S3C_PA_UART + (S3C_UART_OFFSET * CONFIG_S3C_LOWLEVEL_UART_PORT) +#ifdef CONFIG_DEBUG_LL +#define uart_base (S3C_PA_UART + (S3C_UART_OFFSET * CONFIG_DEBUG_S3C_UART)) +#else +#define uart_base 0 +#endif #endif static __inline__ void @@ -66,6 +70,9 @@ uart_rd(unsigned int reg) static void putc(int ch) { + if (!uart_base) + return; + if (uart_rd(S3C2410_UFCON) & S3C2410_UFCON_FIFOMODE) { int level; @@ -118,7 +125,12 @@ static void arch_decomp_error(const char *x) #ifdef CONFIG_S3C_BOOT_UART_FORCE_FIFO static inline void arch_enable_uart_fifo(void) { - u32 fifocon = uart_rd(S3C2410_UFCON); + u32 fifocon; + + if (!uart_base) + return; + + fifocon = uart_rd(S3C2410_UFCON); if (!(fifocon & S3C2410_UFCON_FIFOMODE)) { fifocon |= S3C2410_UFCON_RESETBOTH;
There are two definitions for low-level UART ports for Exynos platform. CONFIG_S3C_LOWLEVEL_UART_PORT is used for printing "Uncompressing Linux... done, booting the kernel." and CONFIG_S3C_UART for other low-level messages. The assumption for both the uart ports is that they are pre-configured in the bootloader. Since they are essentially the same always, it would be good to consolidate them to use only one macro, in this case 'DEBUG_S3C_UART' would be a better option. 'DEBUG_S3C_UART' is defined only if DEBUG_LL is enabled. We can safely disable this option when DEBUG_LL is not defined and we can boot various boards with different UART port settings. Only drawback of this approach is that when DEBUG_LL is not defined, we would be missing the print "Uncompressing Linux... done, booting the kernel." Since CONFIG_S3C_LOWLEVEL_UART_PORT is still used by other Samsung boards, the consolidation applies only for ARCH_EXYNOS. Signed-off-by: Tushar Behera <tushar.behera@linaro.org> --- arch/arm/mach-exynos/include/mach/uncompress.h | 11 ++++++++--- arch/arm/plat-samsung/include/plat/uncompress.h | 16 ++++++++++++++-- 2 files changed, 22 insertions(+), 5 deletions(-)