phone-devel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
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


  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).