[U-Boot] [PATCH 2/5] arm: mxs: Wait when disabling VDDMEM current limiter

Marek Vasut marex at denx.de
Mon Apr 28 03:38:40 CEST 2014


According to i.MX23 datasheet Table 32-17, we must wait for the supply
to settle before disabling the current limiter. Indeed, not waiting a
little here causes the system to crash at times.

Signed-off-by: Marek Vasut <marex at denx.de>
Cc: Stefano Babic <sbabic at denx.de>
---
 arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c b/arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c
index 3baf4dd..de8841a 100644
--- a/arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c
+++ b/arch/arm/cpu/arm926ejs/mxs/spl_mem_init.c
@@ -240,9 +240,14 @@ static void mx23_mem_setup_vddmem(void)
 	struct mxs_power_regs *power_regs =
 		(struct mxs_power_regs *)MXS_POWER_BASE;
 
+	/* We must wait before and after disabling the current limiter! */
+	early_delay(10000);
+
 	clrbits_le32(&power_regs->hw_power_vddmemctrl,
 		POWER_VDDMEMCTRL_ENABLE_ILIMIT);
 
+	early_delay(10000);
+
 }
 
 static void mx23_mem_init(void)
-- 
1.9.2



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