Paul Walmsley wrote:
On OMAP3430ES2, DSS has both an initiator standby CM_IDLEST bit, and a
target idle CM_IDLEST bit.  This is a departure from previous silicon,
which only had an initiator standby bit.

This means we need to test the target idle bit after enabling
dss1_alwon_fclk.  Previous clock code has done the wrong thing since ES2
came out: it's either tested the wrong bit, causing intermittent

    Clock dss1_alwon_fck didn't enable in 100000 tries

messages; or not tested anything at all, causing intermittent crashes during DISPC initialization with:

    Unhandled fault: external abort on non-linefetch (0x1028)

This patch modifies omap2_clk_wait_ready() to wait for the DSS to become
accessible after dss1_alwon_fclk is enabled.

Thanks to Anand Gadiyar <[EMAIL PROTECTED]> for identifying one of the
problem patches.

Signed-off-by: Paul Walmsley <[EMAIL PROTECTED]>

Acked-by: Dirk Behme <[EMAIL PROTECTED]>

 arch/arm/mach-omap2/clock.c           |   30 ++++++++++++++++++++++++------
 arch/arm/mach-omap2/cm-regbits-34xx.h |    4 +++-
 2 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/arch/arm/mach-omap2/clock.c b/arch/arm/mach-omap2/clock.c
index ed15868..1820f75 100644
--- a/arch/arm/mach-omap2/clock.c
+++ b/arch/arm/mach-omap2/clock.c
@@ -244,18 +244,36 @@ static void omap2_clk_wait_ready(struct clk *clk)
        }
/* REVISIT: What are the appropriate exclusions for 34XX? */
-       /* OMAP3: ignore DSS-mod clocks */
-       if (cpu_is_omap34xx() &&
-           ((reg & ~0xff) == (__force 
u32)OMAP34XX_CM_REGADDR(OMAP3430_DSS_MOD, 0) ||
-            (((reg & ~0xff) == (__force u32)OMAP34XX_CM_REGADDR(CORE_MOD, 0)) 
&&
-             clk->enable_bit == OMAP3430_EN_SSI_SHIFT)))
-               return;
+       if (cpu_is_omap34xx()) {
+
+               /* 3430ES1 DSS and SSI have no target idlest bits */
+               if (is_sil_rev_equal_to(OMAP3430_REV_ES1_0) &&
+                   ((reg & ~0xff) == (__force 
u32)OMAP34XX_CM_REGADDR(OMAP3430_DSS_MOD, 0) ||
+                    ((reg & ~0xff) == (__force u32)OMAP34XX_CM_REGADDR(CORE_MOD, 0) 
&&
+                     clk->enable_bit == OMAP3430_EN_SSI_SHIFT)))
+                       return;
+
+               /* Even for 3430ES2 DSS, only wait for dss1_alwon_fclk */
+               if (is_sil_rev_greater_than(OMAP3430_REV_ES1_0) &&
+                   (reg & ~0xff) == (__force u32)OMAP34XX_CM_REGADDR(OMAP3430_DSS_MOD, 
0) &&
+                   clk->enable_bit != OMAP3430_EN_DSS1_SHIFT)
+                       return;
+
+       }
/* Check if both functional and interface clocks
         * are running. */
        bit = 1 << clk->enable_bit;
        if (!(__raw_readl((__force void __iomem *)other_reg) & bit))
                return;
+
+       /* OMAP3430ES2 DSS is an unusual case */
+       if (cpu_is_omap34xx() &&
+           (reg & ~0xff) == (__force u32)OMAP34XX_CM_REGADDR(OMAP3430_DSS_MOD, 0) 
&&
+           clk->enable_bit == OMAP3430_EN_DSS1_SHIFT) {
+               bit = OMAP3430ES2_ST_DSS_IDLE;
+       }
+
        st_reg = ((other_reg & ~0xf0) | 0x20); /* CM_IDLEST* */
omap2_wait_clock_ready((__force void __iomem *)st_reg, bit, clk->name);
diff --git a/arch/arm/mach-omap2/cm-regbits-34xx.h 
b/arch/arm/mach-omap2/cm-regbits-34xx.h
index 6ec66f4..946c552 100644
--- a/arch/arm/mach-omap2/cm-regbits-34xx.h
+++ b/arch/arm/mach-omap2/cm-regbits-34xx.h
@@ -500,7 +500,9 @@
 #define OMAP3430_CM_ICLKEN_DSS_EN_DSS_SHIFT            0
/* CM_IDLEST_DSS */
-#define OMAP3430_ST_DSS                                        (1 << 0)
+#define OMAP3430ES2_ST_DSS_IDLE                                (1 << 1)
+#define OMAP3430ES2_ST_DSS_STDBY                       (1 << 0)
+#define OMAP3430ES1_ST_DSS                             (1 << 0)
/* CM_AUTOIDLE_DSS */
 #define OMAP3430_AUTO_DSS                              (1 << 0)


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