From: Sean Anderson <seanga2@gmail.com>
To: u-boot@lists.denx.de, Leo Liang <ycliang@andestech.com>
Cc: Bin Meng <bmeng.cn@gmail.com>,
Damien Le Moal <Damien.LeMoal@wdc.com>,
Lukasz Majewski <lukma@denx.de>,
Sean Anderson <seanga2@gmail.com>
Subject: [PATCH v2 2/4] k210: clk: Refactor out_of_spec tests
Date: Sat, 11 Sep 2021 13:20:01 -0400 [thread overview]
Message-ID: <20210911172003.899301-2-seanga2@gmail.com> (raw)
In-Reply-To: <20210911172003.899301-1-seanga2@gmail.com>
Everything here sits in a while (true) loop. However, this introduces a
couple of layers of indentation. We can simplify the code by introducing a
single goto instead of using continue/break. This will also make adding
loops in the next patch easier.
Signed-off-by: Sean Anderson <seanga2@gmail.com>
---
(no changes since v1)
drivers/clk/clk_kendryte.c | 105 ++++++++++++++++++-------------------
1 file changed, 52 insertions(+), 53 deletions(-)
diff --git a/drivers/clk/clk_kendryte.c b/drivers/clk/clk_kendryte.c
index 2caa21aec9..69691c4a04 100644
--- a/drivers/clk/clk_kendryte.c
+++ b/drivers/clk/clk_kendryte.c
@@ -709,6 +709,10 @@ TEST_STATIC int k210_pll_calc_config(u32 rate, u32 rate_in,
* Whether we swapped r and od while enforcing frequency limits
*/
bool swapped = false;
+ /*
+ * Whether the intermediate frequencies are out-of-spec
+ */
+ bool out_of_spec;
u64 last_od = od;
u64 last_r = r;
@@ -767,76 +771,71 @@ TEST_STATIC int k210_pll_calc_config(u32 rate, u32 rate_in,
* aren't in spec, try swapping r and od. If everything is
* in-spec, calculate the relative error.
*/
- while (true) {
+again:
+ out_of_spec = false;
+ if (r > max_r) {
+ out_of_spec = true;
+ } else {
/*
- * Whether the intermediate frequencies are out-of-spec
+ * There is no way to only divide once; we need
+ * to examine the frequency with and without the
+ * effect of od.
*/
- bool out_of_spec = false;
+ u64 vco = DIV_ROUND_CLOSEST_ULL(rate_in * f, r);
- if (r > max_r) {
+ if (vco > 1750000000 || vco < 340000000)
out_of_spec = true;
- } else {
- /*
- * There is no way to only divide once; we need
- * to examine the frequency with and without the
- * effect of od.
- */
- u64 vco = DIV_ROUND_CLOSEST_ULL(rate_in * f, r);
+ }
- if (vco > 1750000000 || vco < 340000000)
- out_of_spec = true;
+ if (out_of_spec) {
+ u64 new_r, new_od;
+
+ if (!swapped) {
+ u64 tmp = r;
+
+ r = od;
+ od = tmp;
+ swapped = true;
+ goto again;
}
- if (out_of_spec) {
- if (!swapped) {
- u64 tmp = r;
-
- r = od;
- od = tmp;
- swapped = true;
- continue;
- } else {
- /*
- * Try looking ahead to see if there are
- * additional factors for the same
- * product.
- */
- if (i + 1 < ARRAY_SIZE(factors)) {
- u64 new_r, new_od;
-
- i++;
- new_r = UNPACK_R(factors[i]);
- new_od = UNPACK_OD(factors[i]);
- if (r * od == new_r * new_od) {
- r = new_r;
- od = new_od;
- swapped = false;
- continue;
- }
- i--;
- }
- break;
+ /*
+ * Try looking ahead to see if there are additional
+ * factors for the same product.
+ */
+ if (i + 1 < ARRAY_SIZE(factors)) {
+ i++;
+ new_r = UNPACK_R(factors[i]);
+ new_od = UNPACK_OD(factors[i]);
+ if (r * od == new_r * new_od) {
+ r = new_r;
+ od = new_od;
+ swapped = false;
+ goto again;
}
+ i--;
}
- error = DIV_ROUND_CLOSEST_ULL(f * inv_ratio, r * od);
- /* The lower 16 bits are spurious */
- error = abs((error - BIT(32))) >> 16;
+ /* We ran out of things to try */
+ continue;
+ }
- if (error < best_error) {
- best->r = r;
- best->f = f;
- best->od = od;
- best_error = error;
- }
- break;
+ error = DIV_ROUND_CLOSEST_ULL(f * inv_ratio, r * od);
+ /* The lower 16 bits are spurious */
+ error = abs((error - BIT(32))) >> 16;
+
+ if (error < best_error) {
+ best->r = r;
+ best->f = f;
+ best->od = od;
+ best_error = error;
}
} while (f < 64 && i + 1 < ARRAY_SIZE(factors) && error != 0);
+ log_debug("best error %lld\n", best_error);
if (best_error == S64_MAX)
return -EINVAL;
- log_debug("best error %lld\n", best_error);
return 0;
}
--
2.33.0
next prev parent reply other threads:[~2021-09-11 17:20 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-11 17:20 [PATCH v2 1/4] clk: k210: Fix checking if ulongs are less than 0 Sean Anderson
2021-09-11 17:20 ` Sean Anderson [this message]
2021-09-14 8:45 ` [PATCH v2 2/4] k210: clk: Refactor out_of_spec tests Leo Liang
2021-09-11 17:20 ` [PATCH v2 3/4] test: dm: k210: Reduce duplication in test cases Sean Anderson
2021-09-14 8:48 ` Leo Liang
2021-09-11 17:20 ` [PATCH v2 4/4] clk: k210: Try harder to get the best config Sean Anderson
2021-09-30 4:08 ` Simon Glass
2021-09-14 8:39 ` [PATCH v2 1/4] clk: k210: Fix checking if ulongs are less than 0 Leo Liang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210911172003.899301-2-seanga2@gmail.com \
--to=seanga2@gmail.com \
--cc=Damien.LeMoal@wdc.com \
--cc=bmeng.cn@gmail.com \
--cc=lukma@denx.de \
--cc=u-boot@lists.denx.de \
--cc=ycliang@andestech.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.