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Diffstat (limited to 'target/linux/ipq806x/patches-3.18/135-clk-Avoid-sending-high-rates-to-downstream-clocks-during-set_rate.patch')
-rw-r--r--target/linux/ipq806x/patches-3.18/135-clk-Avoid-sending-high-rates-to-downstream-clocks-during-set_rate.patch129
1 files changed, 0 insertions, 129 deletions
diff --git a/target/linux/ipq806x/patches-3.18/135-clk-Avoid-sending-high-rates-to-downstream-clocks-during-set_rate.patch b/target/linux/ipq806x/patches-3.18/135-clk-Avoid-sending-high-rates-to-downstream-clocks-during-set_rate.patch
deleted file mode 100644
index 02d96ad08a..0000000000
--- a/target/linux/ipq806x/patches-3.18/135-clk-Avoid-sending-high-rates-to-downstream-clocks-during-set_rate.patch
+++ /dev/null
@@ -1,129 +0,0 @@
-Content-Type: text/plain; charset="utf-8"
-MIME-Version: 1.0
-Content-Transfer-Encoding: 7bit
-Subject: [v3, 03/13] clk: Avoid sending high rates to downstream clocks during
- set_rate
-From: Stephen Boyd <sboyd@codeaurora.org>
-X-Patchwork-Id: 6063271
-Message-Id: <1426920332-9340-4-git-send-email-sboyd@codeaurora.org>
-To: Mike Turquette <mturquette@linaro.org>, Stephen Boyd <sboyd@codeaurora.org>
-Cc: linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
- linux-pm@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
- Viresh Kumar <viresh.kumar@linaro.org>
-Date: Fri, 20 Mar 2015 23:45:22 -0700
-
-If a clock is on and we call clk_set_rate() on it we may get into
-a situation where the clock temporarily increases in rate
-dramatically while we walk the tree and call .set_rate() ops. For
-example, consider a case where a PLL feeds into a divider.
-Initially the divider is set to divide by 1 and the PLL is
-running fairly slow (100MHz). The downstream consumer of the
-divider output can only handle rates =< 400 MHz, but the divider
-can only choose between divisors of 1 and 4.
-
- +-----+ +----------------+
- | PLL |-->| div 1 or div 4 |---> consumer device
- +-----+ +----------------+
-
-To achieve a rate of 400MHz on the output of the divider, we
-would have to set the rate of the PLL to 1.6 GHz and then divide
-it by 4. The current code would set the PLL to 1.6GHz first while
-the divider is still set to 1, thus causing the downstream
-consumer of the clock to receive a few clock cycles of 1.6GHz
-clock (far beyond it's maximum acceptable rate). We should be
-changing the divider first before increasing the PLL rate to
-avoid this problem.
-
-Therefore, set the rate of any child clocks that are increasing
-in rate from their current rate so that they can increase their
-dividers if necessary. We assume that there isn't such a thing as
-minimum rate requirements.
-
-Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
-
----
-drivers/clk/clk.c | 34 ++++++++++++++++++++++------------
- 1 file changed, 22 insertions(+), 12 deletions(-)
-
---- a/drivers/clk/clk.c
-+++ b/drivers/clk/clk.c
-@@ -1476,21 +1476,23 @@ static struct clk *clk_propagate_rate_ch
- * walk down a subtree and set the new rates notifying the rate
- * change on the way
- */
--static void clk_change_rate(struct clk *clk)
-+static void clk_change_rate(struct clk *clk, unsigned long best_parent_rate)
- {
- struct clk *child;
- struct hlist_node *tmp;
- unsigned long old_rate;
-- unsigned long best_parent_rate = 0;
- bool skip_set_rate = false;
- struct clk *old_parent;
-
-- old_rate = clk->rate;
-+ hlist_for_each_entry(child, &clk->children, child_node) {
-+ /* Skip children who will be reparented to another clock */
-+ if (child->new_parent && child->new_parent != clk)
-+ continue;
-+ if (child->new_rate > child->rate)
-+ clk_change_rate(child, clk->new_rate);
-+ }
-
-- if (clk->new_parent)
-- best_parent_rate = clk->new_parent->rate;
-- else if (clk->parent)
-- best_parent_rate = clk->parent->rate;
-+ old_rate = clk->rate;
-
- if (clk->new_parent && clk->new_parent != clk->parent) {
- old_parent = __clk_set_parent_before(clk, clk->new_parent);
-@@ -1510,7 +1512,7 @@ static void clk_change_rate(struct clk *
- if (!skip_set_rate && clk->ops->set_rate)
- clk->ops->set_rate(clk->hw, clk->new_rate, best_parent_rate);
-
-- clk->rate = clk_recalc(clk, best_parent_rate);
-+ clk->rate = clk->new_rate;
-
- if (clk->notifier_count && old_rate != clk->rate)
- __clk_notify(clk, POST_RATE_CHANGE, old_rate, clk->rate);
-@@ -1523,12 +1525,13 @@ static void clk_change_rate(struct clk *
- /* Skip children who will be reparented to another clock */
- if (child->new_parent && child->new_parent != clk)
- continue;
-- clk_change_rate(child);
-+ if (child->new_rate != child->rate)
-+ clk_change_rate(child, clk->new_rate);
- }
-
- /* handle the new child who might not be in clk->children yet */
-- if (clk->new_child)
-- clk_change_rate(clk->new_child);
-+ if (clk->new_child && clk->new_child->new_rate != clk->new_child->rate)
-+ clk_change_rate(clk->new_child, clk->new_rate);
- }
-
- /**
-@@ -1556,6 +1559,7 @@ int clk_set_rate(struct clk *clk, unsign
- {
- struct clk *top, *fail_clk;
- int ret = 0;
-+ unsigned long parent_rate;
-
- if (!clk)
- return 0;
-@@ -1589,8 +1593,13 @@ int clk_set_rate(struct clk *clk, unsign
- goto out;
- }
-
-+ if (top->parent)
-+ parent_rate = top->parent->rate;
-+ else
-+ parent_rate = 0;
-+
- /* change the rates */
-- clk_change_rate(top);
-+ clk_change_rate(top, parent_rate);
-
- out:
- clk_prepare_unlock();