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ARM: OMAP2+: l2c: squelch warning dump on power control setting

PATCH New Sekhar Nori 3 participants 3 messages Jul 14, 2014

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Arm (32-bit) Arm sub-architectures OMAP2+ support
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Sekhar Nori

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#0 lore raw

PATCH v2 1/1 ARM: OMAP2+: l2c: squelch warning dump on power control setting

On OMAP SOCs using PL310 controllers, power_ctrl register is not accessible from non-secure software even on PL310 versions which support it. The secure code takes care of setting it up correctly and power transitions are proven on these devices.

For example, AM437x has L2C-310 version r3p3 and ROM code on that device does not support writing to L2C-310 power control register. The L2C driver, however, tries writing to this register for all revisions >= r3p0.

This leads to a warning dump on boot which leads most users to believe that L2 cache is non-functional.

Since the problem is understood, and cannot be addressed through software, replace the warning with a pr_info() while maintaining the WARN_ON() for other truly unexpected scenarios.

Reported-by Nishanth Menon <[email protected]>
Tested-by Felipe Balbi <[email protected]>
Signed-off-by Sekhar Nori <[email protected]>

---
Only description updated since v1

 arch/arm/mach-omap2/omap4-common.c |    4 ++++
 1 file changed, 4 insertions(+)
arch/arm/mach-omap2/omap4-common.c +4 -0
index 326cd98..9139729 100644
@@ -188,6 +188,10 @@ static void omap4_l2c310_write_sec(unsigned long val, unsigned reg)
 		smc_op = OMAP4_MON_L2X0_PREFETCH_INDEX;
 		break;
 
+	case L310_POWER_CTRL:
+		pr_info_once("OMAP L2C310: ROM does not support power control setting\n");
+		return;
+
 	default:
 		WARN_ONCE(1, "OMAP L2C310: ignoring write to reg 0x%x\n", reg);
 		return;
Signature · 1 line
1.7.10.1
#1 lore raw

PATCH v2 1/1 ARM: OMAP2+: l2c: squelch warning dump on power control setting

Quoted 17 lines · Sekhar Nori

On OMAP SOCs using PL310 controllers, power_ctrl register is not accessible from non-secure software even on PL310 versions which support it. The secure code takes care of setting it up correctly and power transitions are proven on these devices.

For example, AM437x has L2C-310 version r3p3 and ROM code on that device does not support writing to L2C-310 power control register. The L2C driver, however, tries writing to this register for all revisions >= r3p0.

This leads to a warning dump on boot which leads most users to believe that L2 cache is non-functional.

Since the problem is understood, and cannot be addressed through software, replace the warning with a pr_info() while maintaining the WARN_ON() for other truly unexpected scenarios.

Quoted 6 lines
Reported-by Nishanth Menon <[email protected]>
Tested-by Felipe Balbi <[email protected]>
Signed-off-by Sekhar Nori <[email protected]>

---
Only description updated since v1

Thanks for update.

Acked-by Santosh Shilimkar <[email protected]>
maintainer
#2 lore raw

PATCH v2 1/1 ARM: OMAP2+: l2c: squelch warning dump on power control setting

Quoted 18 lines · Santosh Shilimkar
Quoted 17 lines · Sekhar Nori

On OMAP SOCs using PL310 controllers, power_ctrl register is not accessible from non-secure software even on PL310 versions which support it. The secure code takes care of setting it up correctly and power transitions are proven on these devices.

For example, AM437x has L2C-310 version r3p3 and ROM code on that device does not support writing to L2C-310 power control register. The L2C driver, however, tries writing to this register for all revisions >= r3p0.

This leads to a warning dump on boot which leads most users to believe that L2 cache is non-functional.

Since the problem is understood, and cannot be addressed through software, replace the warning with a pr_info() while maintaining the WARN_ON() for other truly unexpected scenarios.

Quoted 9 lines
Quoted 6 lines
Reported-by Nishanth Menon <[email protected]>
Tested-by Felipe Balbi <[email protected]>
Signed-off-by Sekhar Nori <[email protected]>

---
Only description updated since v1

Thanks for update.

Acked-by Santosh Shilimkar <[email protected]>

Thanks applying into omap-for-v3.16/fixes.

Tony