Hi Bin,
On 7/10/26 13:03, Bin Meng wrote:
get_cpu_rev() reads the Cortex-A9 SCU configuration register even on
Cortex-A7 based i.MX6UL, i.MX6ULL and i.MX6ULZ SoCs, where the address
is reserved.
Read the SCU configuration only for the raw MX6DL and MX6Q IDs, which
need the core count to distinguish Solo, DualLite, Dual, Quad and Plus
variants. Other SoCs skip the access.
$subject is a bit innacurate. Suggestion:
'''
arm: imx6: Only read SCU for i.MX6DL/i.MX6Q variant detection
get_cpu_rev() reads the Cortex-A9 SCU configuration register for every
i.MX6 variant except i.MX6SL. On the Cortex-A7 based i.MX6UL, i.MX6ULL
and i.MX6ULZ that address is reserved, so the read should not be
performed.
The value is only used to tell the Cortex-A9 variants apart: MX6DL vs
MX6SOLO, and MX6Q vs MX6D. Read the SCU configuration only for the raw
MX6DL and MX6Q digprog IDs and leave 'cfg' at zero for all other SoCs,
which never consumed it.
Fixes: 94db66557997 ("mx6: Distinguish mx6dual from mx6quad")
'''
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
Signed-off-by: Bin Meng <[email protected]>
---
arch/arm/mach-imx/mx6/soc.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/arm/mach-imx/mx6/soc.c b/arch/arm/mach-imx/mx6/soc.c
index 02df86156d4..824e8ca6d8a 100644
--- a/arch/arm/mach-imx/mx6/soc.c
+++ b/arch/arm/mach-imx/mx6/soc.c
@@ -71,15 +71,17 @@ u32 get_nr_cpus(void)
u32 get_cpu_rev(void)
{
struct anatop_regs *anatop = (struct anatop_regs *)ANATOP_BASE_ADDR;
+ struct scu_regs *scu = (struct scu_regs *)SCU_BASE_ADDR;
u32 reg = readl(&anatop->digprog_sololite);
u32 type = ((reg >> 16) & 0xff);
u32 major, cfg = 0;
if (type != MXC_CPU_MX6SL) {
reg = readl(&anatop->digprog);
- struct scu_regs *scu = (struct scu_regs *)SCU_BASE_ADDR;
- cfg = readl(&scu->config) & 3;
type = ((reg >> 16) & 0xff);
+ if (type == MXC_CPU_MX6DL || type == MXC_CPU_MX6Q)
+ cfg = readl(&scu->config) & 3;
+
if (type == MXC_CPU_MX6DL) {
if (!cfg)
type = MXC_CPU_MX6SOLO;
---
base-commit: 8d7bc8add17bbc69a58dfe0002eea039dd2dc1bc
branch: imx6ul
