From: Claudiu Beznea <claudiu.beznea@microchip.com>
To: <sam@ravnborg.org>, <bbrezillon@kernel.org>, <airlied@linux.ie>,
<daniel@ffwll.ch>, <nicolas.ferre@microchip.com>,
<alexandre.belloni@bootlin.com>,
<ludovic.desroches@microchip.com>, <lee.jones@linaro.org>
Cc: <dri-devel@lists.freedesktop.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>, Peter Rosin <peda@axentia.se>
Subject: [PATCH v2 5/6] drm: atmel-hlcdc: prefer a lower pixel-clock than requested
Date: Fri, 13 Dec 2019 17:04:55 +0200 [thread overview]
Message-ID: <1576249496-4849-6-git-send-email-claudiu.beznea@microchip.com> (raw)
In-Reply-To: <1576249496-4849-1-git-send-email-claudiu.beznea@microchip.com>
From: Peter Rosin <peda@axentia.se>
The intention was to only select a higher pixel-clock rate than the
requested, if a slight overclocking would result in a rate significantly
closer to the requested rate than if the conservative lower pixel-clock
rate is selected. The fixed patch has the logic the other way around and
actually prefers the higher frequency. Fix that.
Fixes: f6f7ad323461 ("drm/atmel-hlcdc: allow selecting a higher pixel-clock than requested")
Reported-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Tested-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Peter Rosin <peda@axentia.se>
---
drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
index 721fa88bf71d..10985134ce0b 100644
--- a/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
+++ b/drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_crtc.c
@@ -121,8 +121,8 @@ static void atmel_hlcdc_crtc_mode_set_nofb(struct drm_crtc *c)
int div_low = prate / mode_rate;
if (div_low >= 2 &&
- ((prate / div_low - mode_rate) <
- 10 * (mode_rate - prate / div)))
+ (10 * (prate / div_low - mode_rate) <
+ (mode_rate - prate / div)))
/*
* At least 10 times better when using a higher
* frequency than requested, instead of a lower.
--
2.7.4
next prev parent reply other threads:[~2019-12-13 20:38 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-12-13 15:04 [PATCH v2 0/6] fixes for atmel-hlcdc Claudiu Beznea
2019-12-13 15:04 ` [PATCH v2 1/6] drm: atmel-hlcdc: use double rate for pixel clock only if supported Claudiu Beznea
2019-12-13 15:04 ` [PATCH v2 2/6] drm: atmel-hlcdc: enable clock before configuring timing engine Claudiu Beznea
2019-12-13 15:04 ` [PATCH v2 3/6] mfd: atmel-hlcdc: add struct device member to struct atmel_hlcdc_regmap Claudiu Beznea
2019-12-16 16:17 ` Lee Jones
2019-12-13 15:04 ` [PATCH v2 4/6] mfd: atmel-hlcdc: return in case of error Claudiu Beznea
2019-12-16 16:22 ` Lee Jones
2019-12-16 16:24 ` Lee Jones
2019-12-18 10:02 ` Claudiu.Beznea
2019-12-13 15:04 ` Claudiu Beznea [this message]
2019-12-13 15:04 ` [PATCH v2 6/6] Revert "drm: atmel-hlcdc: enable sys_clk during initalization." Claudiu Beznea
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