---

yaml --- r: 363128 b: refs/heads/master c: 3f7a73b h: refs/heads/master v: v3
git-mirror · Mar 25, 2013 · 91ac912 · 91ac912
1 parent 3f29f85
commit 91ac912
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Showing 2 changed files with 14 additions and 1 deletion.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 97f00f7120fe3396302693cdc4b1d11bbacad963
+refs/heads/master: 3f7a73b57c2f57aa25342ebdb7312f78c68502eb
diff --git a/trunk/drivers/ssbi/ssbi.c b/trunk/drivers/ssbi/ssbi.c
@@ -87,6 +87,15 @@ static inline void ssbi_writel(struct msm_ssbi *ssbi, u32 val, u32 reg)
 	writel(val, ssbi->base + reg);
 }
 
+/*
+ * Via private exchange with one of the original authors, the hardware
+ * should generally finish a transaction in about 5us.  The worst
+ * case, is when using the arbiter and both other CPUs have just
+ * started trying to use the SSBI bus will result in a time of about
+ * 20us.  It should never take longer than this.
+ *
+ * As such, this wait merely spins, with a udelay.
+ */
 static int ssbi_wait_mask(struct msm_ssbi *ssbi, u32 set_mask, u32 clr_mask)
 {
 	u32 timeout = SSBI_TIMEOUT_US;
@@ -161,6 +170,10 @@ msm_ssbi_write_bytes(struct msm_ssbi *ssbi, u16 addr, u8 *buf, int len)
 	return ret;
 }
 
+/*
+ * See ssbi_wait_mask for an explanation of the time and the
+ * busywait.
+ */
 static inline int
 msm_ssbi_pa_transfer(struct msm_ssbi *ssbi, u32 cmd, u8 *data)
 {