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Subject[PATCH 03/33] clk: composite: allow round_rate to scale past LONG_MAX on 32 bit systems
Date
Defining the return value of round_rate as a long and returning error codes
as well as the rounded-clock value in the return value of a
clk_ops->round_rate callback means that its not possible to return a clock
greater than LONG_MAX Hz on a 32 bit system.

This patch changes the handling of the return value from round_rate() such
that zero indicates an unusable clock and non-zero indicates a successfully
rounded clock giving us a full range of 1 Hz to ULONG_MAX Hz on 32 bit
systems.

Implementations of round_rate() must either return a rounded-clock or zero
to indicate error.

Signed-off-by: Bryan O'Donoghue <pure.logic@nexus-software.ie>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: linux-clk@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
drivers/clk/clk-composite.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/clk/clk-composite.c b/drivers/clk/clk-composite.c
index f3707c3..2090b74 100644
--- a/drivers/clk/clk-composite.c
+++ b/drivers/clk/clk-composite.c
@@ -66,7 +66,7 @@ static int clk_composite_determine_rate(struct clk_hw *hw,
long tmp_rate, best_rate = 0;
unsigned long rate_diff;
unsigned long best_rate_diff = ULONG_MAX;
- long rate;
+ unsigned long rate;
int i;

if (rate_hw && rate_ops && rate_ops->determine_rate) {
@@ -83,8 +83,8 @@ static int clk_composite_determine_rate(struct clk_hw *hw,

rate = rate_ops->round_rate(rate_hw, req->rate,
&req->best_parent_rate);
- if (rate < 0)
- return rate;
+ if (!rate)
+ return -EINVAL;

req->rate = rate;
return 0;
@@ -99,7 +99,7 @@ static int clk_composite_determine_rate(struct clk_hw *hw,

tmp_rate = rate_ops->round_rate(rate_hw, req->rate,
&parent_rate);
- if (tmp_rate < 0)
+ if (tmp_rate == 0)
continue;

rate_diff = abs(req->rate - tmp_rate);
--
2.7.4
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