[U-Boot] [PATCH 0/1] fix ARM DCC support for ARMv7 based cores (e.g. CortexA)

[U-Boot] [PATCH 0/1] fix ARM DCC support for ARMv7 based cores (e.g. CortexA)

[Alexander Merkle]

arm_dcc.c supported ARMv4 (ARM7) to ARMv6 (ARM11) correctly. All recent
CortexA/ARMv7 based cores share the mrc/mcr coprocessor calls of ARMv6.
Due to the missing #ifdef the ARM7/ARMv4 calls are used as soon as
CONFIG_CPU_V7 is defined. This results in an undefined instruction exception.


Alexander Merkle (1):
  fix ARM DCC support for ARMv7 based cores (e.g. CortexA)

 drivers/serial/arm_dcc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

-- 
2.1.4

[U-Boot] [PATCH] fix ARM DCC support for ARMv7 based cores (e.g. CortexA)

[Alexander Merkle]

Signed-off-by: Alexander Merkle <alexander.merkle@lauterbach.com>
---

 drivers/serial/arm_dcc.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/serial/arm_dcc.c b/drivers/serial/arm_dcc.c
index 5dfb02f..e777737 100644
--- a/drivers/serial/arm_dcc.c
+++ b/drivers/serial/arm_dcc.c
@@ -29,9 +29,9 @@
 #include <common.h>
 #include <serial.h>
 
-#if defined(CONFIG_CPU_V6)
+#if defined(CONFIG_CPU_V6) || defined(CONFIG_CPU_V7)
 /*
- * ARMV6
+ * ARMV6 & ARMV7
  */
 #define DCC_RBIT	(1 << 30)
 #define DCC_WBIT	(1 << 29)
-- 
2.1.4

[U-Boot] [PATCH 0/1] fix ARM DCC support for ARMv7 based cores (e.g. CortexA)

[Albert ARIBAUD]

Hello Alexander,

On Mon, 26 Jan 2015 14:13:16 +0100, Alexander Merkle
<alexander.merkle@lauterbach.com> wrote:
> 
> arm_dcc.c supported ARMv4 (ARM7) to ARMv6 (ARM11) correctly. All recent
> CortexA/ARMv7 based cores share the mrc/mcr coprocessor calls of ARMv6.
> Due to the missing #ifdef the ARM7/ARMv4 calls are used as soon as
> CONFIG_CPU_V7 is defined. This results in an undefined instruction exception.

IIUC, the only board that uses ARM DCC serial is the Zynq, and it
gets it to work by #define'ing CONFIG_CPU_V6 in its include config
file despite being ARMv7. Am I right in assuming this #define was
actually a hack to get around the issue you're fixing here, and that it
can and should be removed from the Zinq include? If so, can you please
post a v2 of your patch which does the removal too?

(BTW, no need for a cover letter when there's only one patch in the
"series" IMO)

Amicalement,
-- 
Albert.

[U-Boot] [PATCH 0/1] fix ARM DCC support for ARMv7 based cores (e.g. CortexA)

[Albert ARIBAUD]

Hello Alexander,

On Sun, 1 Feb 2015 10:02:47 +0100, Albert ARIBAUD
<albert.u.boot@aribaud.net> wrote:
> Hello Alexander,
> 
> On Mon, 26 Jan 2015 14:13:16 +0100, Alexander Merkle
> <alexander.merkle@lauterbach.com> wrote:
> > 
> > arm_dcc.c supported ARMv4 (ARM7) to ARMv6 (ARM11) correctly. All recent
> > CortexA/ARMv7 based cores share the mrc/mcr coprocessor calls of ARMv6.
> > Due to the missing #ifdef the ARM7/ARMv4 calls are used as soon as
> > CONFIG_CPU_V7 is defined. This results in an undefined instruction exception.
> 
> IIUC, the only board that uses ARM DCC serial is the Zynq, and it
> gets it to work by #define'ing CONFIG_CPU_V6 in its include config
> file despite being ARMv7. Am I right in assuming this #define was
> actually a hack to get around the issue you're fixing here, and that it
> can and should be removed from the Zinq include? If so, can you please
> post a v2 of your patch which does the removal too?
> 
> (BTW, no need for a cover letter when there's only one patch in the
> "series" IMO)

Ping.

Amicalement,
-- 
Albert.