From: Mark Brown <broonie@kernel.org> To: Javier Martinez Canillas <javierm@redhat.com> Cc: "Geert Uytterhoeven" <geert@linux-m68k.org>, "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" <devicetree@vger.kernel.org>, "Linux Fbdev development list" <linux-fbdev@vger.kernel.org>, "Linux PWM List" <linux-pwm@vger.kernel.org>, "David Airlie" <airlied@linux.ie>, "Daniel Vetter" <daniel.vetter@ffwll.ch>, "Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>, "DRI Development" <dri-devel@lists.freedesktop.org>, "Liam Girdwood" <lgirdwood@gmail.com>, "Rob Herring" <robh+dt@kernel.org>, "Noralf Trønnes" <noralf@tronnes.org>, "Thierry Reding" <thierry.reding@gmail.com>, "Maxime Ripard" <maxime@cerno.tech>, "Thomas Zimmermann" <tzimmermann@suse.de>, "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>, "Lee Jones" <lee.jones@linaro.org>, "Andy Shevchenko" <andriy.shevchenko@linux.intel.com>, "Sam Ravnborg" <sam@ravnborg.org> Subject: Re: [PATCH v2 0/4] drm/tiny: Add driver for Solomon SSD1307 OLED displays Date: Tue, 8 Feb 2022 15:18:14 +0000 [thread overview] Message-ID: <YgKJtjoFMSzxNiiI@sirena.org.uk> (raw) In-Reply-To: <f178de92-7cb1-dcc5-1f60-9ccfc56bc0a4@redhat.com> [-- Attachment #1: Type: text/plain, Size: 1001 bytes --] On Tue, Feb 08, 2022 at 04:10:49PM +0100, Javier Martinez Canillas wrote: > On 2/8/22 15:19, Geert Uytterhoeven wrote: > > - "time ls" on the serial console (no files in the current directory, > > so nothing to print) increases from 0.86s to 1.92s, so the system is > > more loaded. As ssd1307fb relied on deferred I/O too, the slowdown > > might be (partly) due to redrawing of the visual artefacts > > mentioned above. > I was trying to first have the driver and then figure out how to optimize > it. For v3 I'm using regmap to access instead of the I2C layer directly. > I noticed that this is even slower but it makes the driver more clean and > allows to support both I2C and SPI (untested but will include it as a WIP). I wouldn't have expected regmap to add huge overhead relative to I2C, partly predicated on I2C being rather slow itself. There will be some overhead for concurrency protection and data marshalling but for I2C clocked at normal speeds it's surprising. [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --]
WARNING: multiple messages have this Message-ID (diff)
From: Mark Brown <broonie@kernel.org> To: Javier Martinez Canillas <javierm@redhat.com> Cc: "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" <devicetree@vger.kernel.org>, "Linux Fbdev development list" <linux-fbdev@vger.kernel.org>, "Noralf Trønnes" <noralf@tronnes.org>, "Sam Ravnborg" <sam@ravnborg.org>, "Linux PWM List" <linux-pwm@vger.kernel.org>, "David Airlie" <airlied@linux.ie>, "Daniel Vetter" <daniel.vetter@ffwll.ch>, "Linux Kernel Mailing List" <linux-kernel@vger.kernel.org>, "DRI Development" <dri-devel@lists.freedesktop.org>, "Liam Girdwood" <lgirdwood@gmail.com>, "Rob Herring" <robh+dt@kernel.org>, "Geert Uytterhoeven" <geert@linux-m68k.org>, "Maxime Ripard" <maxime@cerno.tech>, "Thomas Zimmermann" <tzimmermann@suse.de>, "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>, "Thierry Reding" <thierry.reding@gmail.com>, "Andy Shevchenko" <andriy.shevchenko@linux.intel.com>, "Lee Jones" <lee.jones@linaro.org> Subject: Re: [PATCH v2 0/4] drm/tiny: Add driver for Solomon SSD1307 OLED displays Date: Tue, 8 Feb 2022 15:18:14 +0000 [thread overview] Message-ID: <YgKJtjoFMSzxNiiI@sirena.org.uk> (raw) In-Reply-To: <f178de92-7cb1-dcc5-1f60-9ccfc56bc0a4@redhat.com> [-- Attachment #1: Type: text/plain, Size: 1001 bytes --] On Tue, Feb 08, 2022 at 04:10:49PM +0100, Javier Martinez Canillas wrote: > On 2/8/22 15:19, Geert Uytterhoeven wrote: > > - "time ls" on the serial console (no files in the current directory, > > so nothing to print) increases from 0.86s to 1.92s, so the system is > > more loaded. As ssd1307fb relied on deferred I/O too, the slowdown > > might be (partly) due to redrawing of the visual artefacts > > mentioned above. > I was trying to first have the driver and then figure out how to optimize > it. For v3 I'm using regmap to access instead of the I2C layer directly. > I noticed that this is even slower but it makes the driver more clean and > allows to support both I2C and SPI (untested but will include it as a WIP). I wouldn't have expected regmap to add huge overhead relative to I2C, partly predicated on I2C being rather slow itself. There will be some overhead for concurrency protection and data marshalling but for I2C clocked at normal speeds it's surprising. [-- Attachment #2: signature.asc --] [-- Type: application/pgp-signature, Size: 488 bytes --]
next prev parent reply other threads:[~2022-02-08 15:18 UTC|newest] Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-02-04 13:43 [PATCH v2 0/4] drm/tiny: Add driver for Solomon SSD1307 OLED displays Javier Martinez Canillas 2022-02-04 13:43 ` Javier Martinez Canillas 2022-02-04 13:43 ` [PATCH v2 1/4] drm/format-helper: Add drm_fb_{xrgb8888,gray8}_to_mono_reversed() Javier Martinez Canillas 2022-02-04 13:43 ` [PATCH v2 1/4] drm/format-helper: Add drm_fb_{xrgb8888, gray8}_to_mono_reversed() Javier Martinez Canillas 2022-02-04 15:52 ` [PATCH v2 1/4] drm/format-helper: Add drm_fb_{xrgb8888,gray8}_to_mono_reversed() Thomas Zimmermann 2022-02-04 15:52 ` Thomas Zimmermann 2022-02-04 16:00 ` Thomas Zimmermann 2022-02-04 19:31 ` Javier Martinez Canillas 2022-02-04 19:31 ` Javier Martinez Canillas 2022-02-04 20:35 ` Thomas Zimmermann 2022-02-04 20:35 ` Thomas Zimmermann 2022-02-04 21:02 ` Ilia Mirkin 2022-02-04 21:02 ` [PATCH v2 1/4] drm/format-helper: Add drm_fb_{xrgb8888, gray8}_to_mono_reversed() Ilia Mirkin 2022-02-07 12:44 ` Thomas Zimmermann 2022-02-04 13:43 ` [PATCH v2 2/4] drm/tiny: Add driver for Solomon SSD130X OLED displays Javier Martinez Canillas 2022-02-04 13:43 ` Javier Martinez Canillas 2022-02-04 14:26 ` Andy Shevchenko 2022-02-04 14:26 ` Andy Shevchenko 2022-02-04 19:19 ` Javier Martinez Canillas 2022-02-04 19:19 ` Javier Martinez Canillas 2022-02-05 13:04 ` Andy Shevchenko 2022-02-05 13:04 ` Andy Shevchenko 2022-02-05 17:40 ` Javier Martinez Canillas 2022-02-05 17:40 ` Javier Martinez Canillas 2022-02-04 13:43 ` [PATCH v2 3/4] MAINTAINERS: Add entry for Solomon SSD130X OLED displays DRM driver Javier Martinez Canillas 2022-02-04 13:43 ` Javier Martinez Canillas 2022-02-04 13:57 ` Andy Shevchenko 2022-02-04 13:57 ` Andy Shevchenko 2022-02-04 14:12 ` Javier Martinez Canillas 2022-02-04 14:12 ` Javier Martinez Canillas 2022-02-04 14:28 ` Andy Shevchenko 2022-02-04 14:28 ` Andy Shevchenko 2022-02-04 14:33 ` Javier Martinez Canillas 2022-02-04 14:33 ` Javier Martinez Canillas 2022-02-04 13:43 ` [PATCH v2 4/4] dt-bindings: display: ssd1307fb: Add myself as binding co-maintainer Javier Martinez Canillas 2022-02-04 13:43 ` Javier Martinez Canillas 2022-02-09 22:14 ` Rob Herring 2022-02-09 22:14 ` Rob Herring 2022-02-04 14:31 ` [PATCH v2 0/4] drm/tiny: Add driver for Solomon SSD1307 OLED displays Geert Uytterhoeven 2022-02-04 14:31 ` Geert Uytterhoeven 2022-02-04 14:37 ` Javier Martinez Canillas 2022-02-04 14:37 ` Javier Martinez Canillas 2022-02-08 14:19 ` Geert Uytterhoeven 2022-02-08 14:19 ` Geert Uytterhoeven 2022-02-08 15:10 ` Javier Martinez Canillas 2022-02-08 15:10 ` Javier Martinez Canillas 2022-02-08 15:18 ` Mark Brown [this message] 2022-02-08 15:18 ` Mark Brown 2022-02-08 15:32 ` Javier Martinez Canillas 2022-02-08 15:32 ` Javier Martinez Canillas 2022-02-08 15:23 ` Geert Uytterhoeven 2022-02-08 15:23 ` Geert Uytterhoeven 2022-02-08 15:40 ` Javier Martinez Canillas 2022-02-08 15:40 ` Javier Martinez Canillas 2022-02-08 17:19 ` Javier Martinez Canillas 2022-02-08 17:19 ` Javier Martinez Canillas 2022-02-09 13:47 ` Andy Shevchenko 2022-02-09 13:47 ` Andy Shevchenko 2022-02-09 14:27 ` Geert Uytterhoeven 2022-02-09 14:27 ` Geert Uytterhoeven 2022-02-09 14:42 ` Javier Martinez Canillas 2022-02-09 14:42 ` Javier Martinez Canillas 2022-02-09 15:32 ` Andy Shevchenko 2022-02-09 15:32 ` Andy Shevchenko 2022-02-10 8:32 ` Maxime Ripard 2022-02-10 8:32 ` Maxime Ripard
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