From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: Re: [PATCH v3 1/7] mfd: cros_ec: spi: calculate delay between transfers correctly Date: Tue, 20 May 2014 09:43:58 +0100 Message-ID: <20140520084358.GB24991@lee--X1> References: <1398879850-9111-1-git-send-email-dianders@chromium.org> <1398879850-9111-2-git-send-email-dianders@chromium.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Content-Disposition: inline In-Reply-To: <1398879850-9111-2-git-send-email-dianders@chromium.org> Sender: linux-samsung-soc-owner@vger.kernel.org To: Doug Anderson Cc: swarren@nvidia.com, wsa@the-dreams.de, abrestic@chromium.org, dgreid@chromium.org, olof@lixom.net, sjg@chromium.org, linux-samsung-soc@vger.kernel.org, linux-tegra@vger.kernel.org, David Hendricks , sameo@linux.intel.com, linux-kernel@vger.kernel.org List-Id: linux-tegra@vger.kernel.org > From: David Hendricks >=20 > To avoid spamming the EC we calculate the time between the previous > transfer and the current transfer and force a delay if the time delta > is too small. >=20 > However, a small miscalculation causes the delay period to be > far too short. Most noticably this impacts commands with a long > turnaround time such as EC firmware reads and writes. >=20 > Signed-off-by: David Hendricks > Signed-off-by: Doug Anderson > Acked-by: Lee Jones > Reviewed-by: Simon Glass > Tested-by: Andrew Bresticker > Tested-by: Stephen Warren > --- > Changes in v3: None > Changes in v2: None >=20 > drivers/mfd/cros_ec_spi.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Applied, thanks. > diff --git a/drivers/mfd/cros_ec_spi.c b/drivers/mfd/cros_ec_spi.c > index 84af8d7..c185eb6 100644 > --- a/drivers/mfd/cros_ec_spi.c > +++ b/drivers/mfd/cros_ec_spi.c > @@ -219,7 +219,7 @@ static int cros_ec_command_spi_xfer(struct cros_e= c_device *ec_dev, > ktime_get_ts(&ts); > delay =3D timespec_to_ns(&ts) - ec_spi->last_transfer_ns; > if (delay < EC_SPI_RECOVERY_TIME_NS) > - ndelay(delay); > + ndelay(EC_SPI_RECOVERY_TIME_NS - delay); > } > =20 > /* Transmit phase - send our message */ --=20 Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org =E2=94=82 Open source software for ARM SoCs =46ollow Linaro: Facebook | Twitter | Blog