From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dmitry Torokhov Subject: Re: [PATCH] Input: ads7877: Remove bitrotted comment Date: Tue, 22 Apr 2014 17:39:28 -0700 Message-ID: <20140423003928.GB22547@core.coreip.homeip.net> References: <1398201501-13470-1-git-send-email-broonie@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pa0-f53.google.com ([209.85.220.53]:53856 "EHLO mail-pa0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750927AbaDWAjc (ORCPT ); Tue, 22 Apr 2014 20:39:32 -0400 Received: by mail-pa0-f53.google.com with SMTP id ld10so173168pab.26 for ; Tue, 22 Apr 2014 17:39:31 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1398201501-13470-1-git-send-email-broonie@kernel.org> Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Mark Brown Cc: Michael Hennerich , linux-input@vger.kernel.org, linaro-kernel@lists.linaro.org, Mark Brown On Tue, Apr 22, 2014 at 10:18:21PM +0100, Mark Brown wrote: > From: Mark Brown > > While searching for users of spi_async() I found a reference in the ad7877 > driver to using it to initiate data transfer from the interrupt handler. > However there is no code for this, instead the interrupt handler is a > threaded handler and uses spi_sync() instead. > > Remove the bitrotted comment, though in actual fact the use case mentioned > is a great use for spi_async() since it would cut down on latency handling > the interrupt by saving us a context switch before we start SPI. > > This was previously implemented, it was removed in commit b534422b2d11 > (Input: ad7877 - switch to using threaded IRQ) for code complexity reasons. > It may be better to revert that commit instead. Hmm, maybe.. although I think original would cause device 'stuck' if call to spi_async() fails, so probably not a straight revert... > > Signed-off-by: Mark Brown > --- > drivers/input/touchscreen/ad7877.c | 5 ----- > 1 file changed, 5 deletions(-) > > diff --git a/drivers/input/touchscreen/ad7877.c b/drivers/input/touchscreen/ad7877.c > index 6793c85903ae..523865daa1d3 100644 > --- a/drivers/input/touchscreen/ad7877.c > +++ b/drivers/input/touchscreen/ad7877.c > @@ -210,11 +210,6 @@ static bool gpio3; > module_param(gpio3, bool, 0); > MODULE_PARM_DESC(gpio3, "If gpio3 is set to 1 AUX3 acts as GPIO3"); > > -/* > - * ad7877_read/write are only used for initial setup and for sysfs controls. > - * The main traffic is done using spi_async() in the interrupt handler. > - */ > - > static int ad7877_read(struct spi_device *spi, u16 reg) > { > struct ser_req *req; > -- > 1.9.2 > > -- Dmitry