From: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
To: linux-arm-msm@vger.kernel.org
Cc: konrad.dybcio@somainline.org, marijn.suijten@somainline.org,
martin.botka@somainline.org, phone-devel@vger.kernel.org,
linux-kernel@vger.kernel.org, robdclark@gmail.com,
sean@poorly.run, airlied@linux.ie, daniel@ffwll.ch,
dri-devel@lists.freedesktop.org, freedreno@lists.freedesktop.org,
AngeloGioacchino Del Regno
<angelogioacchino.delregno@somainline.org>
Subject: [PATCH 1/5] drm/msm/dsi_pll_10nm: Fix dividing the same numbers twice
Date: Sat, 9 Jan 2021 14:51:08 +0100 [thread overview]
Message-ID: <20210109135112.147759-2-angelogioacchino.delregno@somainline.org> (raw)
In-Reply-To: <20210109135112.147759-1-angelogioacchino.delregno@somainline.org>
In function dsi_pll_calc_dec_frac we are calculating the decimal
div start parameter by dividing the decimal multiple by the
fractional multiplier: the remainder of that operation is stored
to then get programmed to the fractional divider registers of
the PLL.
It's useless to call div_u64_rem to get the remainder and *then*
call div_u64 to get the division result, as the first is already
giving that result: let's fix it by just caring about the result
of div_u64_rem.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
---
drivers/gpu/drm/msm/dsi/pll/dsi_pll_10nm.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/msm/dsi/pll/dsi_pll_10nm.c b/drivers/gpu/drm/msm/dsi/pll/dsi_pll_10nm.c
index 6ac04fc303f5..2c1fcf092ab8 100644
--- a/drivers/gpu/drm/msm/dsi/pll/dsi_pll_10nm.c
+++ b/drivers/gpu/drm/msm/dsi/pll/dsi_pll_10nm.c
@@ -172,9 +172,7 @@ static void dsi_pll_calc_dec_frac(struct dsi_pll_10nm *pll)
multiplier = 1 << config->frac_bits;
dec_multiple = div_u64(pll_freq * multiplier, divider);
- div_u64_rem(dec_multiple, multiplier, &frac);
-
- dec = div_u64(dec_multiple, multiplier);
+ dec = div_u64_rem(dec_multiple, multiplier, &frac);
if (pll_freq <= 1900000000UL)
regs->pll_prop_gain_rate = 8;
--
2.29.2
next prev parent reply other threads:[~2021-01-09 13:52 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-09 13:51 [PATCH 0/5] Clock fixes for DSI 10nm PLL AngeloGioacchino Del Regno
2021-01-09 13:51 ` AngeloGioacchino Del Regno [this message]
2021-01-09 13:51 ` [PATCH 2/5] drm/msm/dsi_pll_10nm: Solve TODO for multiplier frac_bits assignment AngeloGioacchino Del Regno
2021-01-09 13:51 ` [PATCH 3/5] drm/msm/dsi_pll_10nm: Fix bad VCO rate calculation and prescaler AngeloGioacchino Del Regno
2021-01-31 19:50 ` Rob Clark
2021-02-01 10:11 ` AngeloGioacchino Del Regno
2021-02-01 15:47 ` Rob Clark
2021-02-01 17:05 ` Rob Clark
2021-02-01 17:18 ` Rob Clark
2021-02-01 17:31 ` Rob Clark
2021-02-02 14:32 ` AngeloGioacchino Del Regno
2021-02-02 18:45 ` Rob Clark
2021-02-02 18:46 ` AngeloGioacchino Del Regno
2021-02-02 19:08 ` Rob Clark
2021-02-02 21:35 ` Rob Clark
2021-01-09 13:51 ` [PATCH 4/5] drm/msm/dsi_pll_10nm: Fix variable usage for pll_lockdet_rate AngeloGioacchino Del Regno
2021-01-09 13:51 ` [PATCH 5/5] drm/msm/dsi_pll_10nm: Convert pr_err prints to DRM_DEV_ERROR AngeloGioacchino Del Regno
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=20210109135112.147759-2-angelogioacchino.delregno@somainline.org \
--to=angelogioacchino.delregno@somainline.org \
--cc=airlied@linux.ie \
--cc=daniel@ffwll.ch \
--cc=dri-devel@lists.freedesktop.org \
--cc=freedreno@lists.freedesktop.org \
--cc=konrad.dybcio@somainline.org \
--cc=linux-arm-msm@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=marijn.suijten@somainline.org \
--cc=martin.botka@somainline.org \
--cc=phone-devel@vger.kernel.org \
--cc=robdclark@gmail.com \
--cc=sean@poorly.run \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).