From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751667Ab1AEAdI (ORCPT ); Tue, 4 Jan 2011 19:33:08 -0500 Received: from mail-ww0-f44.google.com ([74.125.82.44]:52669 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750957Ab1AEAdF (ORCPT ); Tue, 4 Jan 2011 19:33:05 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=QEHgj8S0mNmyuEGRofX8AUHh+Q9drk5xRXujznEipIQdVgsL+OylgjhNwS3fNL6NzT Tc8ytFqxLLa5AExv2KHbcDJLewr2zxs/V6lWIglN52R3T8eswcs+b/TOTBWzKyzwmLQr XtYcmbX5HvZt8oSvo+dRsuanbkTmc20/yPJEs= Subject: Re: [PATCH] backlight: l4f00242t03: Fix reset sequence From: Alberto Panizzo To: Andrew Morton Cc: Richard Purdie , Marek Vasut , Tejun Heo , Axel Lin , linux-kernel In-Reply-To: <20110104155920.1aafcf0c.akpm@linux-foundation.org> References: <1290964433.3016.2.camel@realization> <20110104155920.1aafcf0c.akpm@linux-foundation.org> Content-Type: text/plain; charset="UTF-8" Date: Wed, 05 Jan 2011 01:32:55 +0100 Message-ID: <1294187575.2509.276.camel@realization> Mime-Version: 1.0 X-Mailer: Evolution 2.30.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2011-01-04 at 15:59 -0800, Andrew Morton wrote: > On Sun, 28 Nov 2010 18:13:53 +0100 > Alberto Panizzo wrote: > > > The reset command is part of the init sequence and it take effect > > only if the lcd is powered. > > > > Signed-off-by: Alberto Panizzo > > --- > > > > This patch is built on top of: > > http://userweb.kernel.org/~akpm/mmotm/broken-out/drivers-video-backlight-l4f00242t03c-full-implement-fb-power-states-for-this-lcd.patch > > > > drivers/video/backlight/l4f00242t03.c | 3 ++- > > 1 files changed, 2 insertions(+), 1 deletions(-) > > > > diff --git a/drivers/video/backlight/l4f00242t03.c b/drivers/video/backlight/l4f00242t03.c > > index 5d25743..c04aa90 100644 > > --- a/drivers/video/backlight/l4f00242t03.c > > +++ b/drivers/video/backlight/l4f00242t03.c > > @@ -62,6 +62,8 @@ static void l4f00242t03_lcd_init(struct spi_device *spi) > > regulator_enable(priv->core_reg); > > } > > > > + l4f00242t03_reset(pdata->reset_gpio); > > + > > gpio_set_value(pdata->data_enable_gpio, 1); > > msleep(60); > > spi_write(spi, (const u8 *)cmd, ARRAY_SIZE(cmd) * sizeof(u16)); > > @@ -225,7 +227,6 @@ static int __devinit l4f00242t03_probe(struct spi_device *spi) > > } > > > > /* Init the LCD */ > > - l4f00242t03_reset(pdata->reset_gpio); > > l4f00242t03_lcd_init(spi); > > priv->lcd_state = FB_BLANK_VSYNC_SUSPEND; > > l4f00242t03_lcd_power_set(priv->ld, FB_BLANK_UNBLANK); > > What were the user-visible effects of the bug which you just fixed? > > Please always include this info when sending a bugfix! Because without > that info it's much harder to work out whether we should backport the > fix into earlier kernels and it's harder for end-users and distro > maintainers to work out if the patch will fix particular behaviour > which they or their customers are seeing. > The effect of the bug was that the sequence: set lcd power_state to FB_BLANK_POWERDOWN set lcd power_state to FB_BLANK_UNBLANK Did not produced a complete reboot of the LCD which was showing fuzzy colours. This was not experienced before implementing correctly all the LCD power states with the patch [1]. Since before the patch [1] the regulators were not touched and the LCD shutdown was reached with a register write. After the patch [1] a complete boot sequence with an initial reset is needed for the display every time the LCD is powered up. drivers-video-backlight-l4f00242t03c-full-implement-fb-power-states-for-this-lcd.patch Best Regards, -- Alberto! Be Persistent! - Greg Kroah-Hartman (FOSDEM 2010)