From mboxrd@z Thu Jan 1 00:00:00 1970 From: u.kleine-koenig@pengutronix.de (Uwe =?iso-8859-1?Q?Kleine-K=F6nig?=) Date: Mon, 30 Jan 2012 08:15:02 +0100 Subject: [PATCH 1/6] mfd: mc13xxx-core: ADC conv: ack existing pending irqs before requesting In-Reply-To: <1327876408-22528-2-git-send-email-marc@cpdesign.com.au> References: <1327876408-22528-1-git-send-email-marc@cpdesign.com.au> <1327876408-22528-2-git-send-email-marc@cpdesign.com.au> Message-ID: <20120130071502.GF6305@pengutronix.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Mon, Jan 30, 2012 at 09:33:23AM +1100, Marc Reilly wrote: > This acks any existing pending ADCDONE irqs before requesting one for the > new conversion, rather than after. > > Signed-off-by: Marc Reilly > --- > drivers/mfd/mc13xxx-core.c | 2 +- > 1 files changed, 1 insertions(+), 1 deletions(-) > > diff --git a/drivers/mfd/mc13xxx-core.c b/drivers/mfd/mc13xxx-core.c > index 1fd265d..8cb83ef 100644 > --- a/drivers/mfd/mc13xxx-core.c > +++ b/drivers/mfd/mc13xxx-core.c > @@ -561,9 +561,9 @@ int mc13xxx_adc_do_conversion(struct mc13xxx *mc13xxx, unsigned int mode, > } > > dev_dbg(mc13xxx->dev, "%s: request irq\n", __func__); > + mc13xxx_irq_ack(mc13xxx, MC13XXX_IRQ_ADCDONE); > mc13xxx_irq_request(mc13xxx, MC13XXX_IRQ_ADCDONE, > mc13xxx_handler_adcdone, __func__, &adcdone_data); > - mc13xxx_irq_ack(mc13xxx, MC13XXX_IRQ_ADCDONE); > > mc13xxx_reg_write(mc13xxx, MC13XXX_ADC0, adc0); > mc13xxx_reg_write(mc13xxx, MC13XXX_ADC1, adc1); hmm, I wonder if the irq should be acked if it's not requested. The code doesn't do error checking, but consider mc13xxx_irq_request fails because the irq is already requested by someone else. Then acking before requesting is wrong, isn't it? Maybe irq_request should ack the irq or maybe better introduce a function mc13xxx_irq_request_and_ack that acks only if the request part is OK? Best regards Uwe -- Pengutronix e.K. | Uwe Kleine-K?nig | Industrial Linux Solutions | http://www.pengutronix.de/ |