From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:67c:670:201:290:27ff:fe1d:cc33]) by bombadil.infradead.org with esmtps (Exim 4.87 #1 (Red Hat Linux)) id 1eCjhB-0003L3-7Z for barebox@lists.infradead.org; Thu, 09 Nov 2017 10:04:27 +0000 Date: Thu, 9 Nov 2017 11:04:00 +0100 From: Sascha Hauer Message-ID: <20171109100400.swaevd4zzqekhcpi@pengutronix.de> References: <20171108153308.17351-1-o.rempel@pengutronix.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20171108153308.17351-1-o.rempel@pengutronix.de> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "barebox" Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: [PATCH v1] i.MX: esdhc: optimize set_ios path To: Oleksij Rempel Cc: barebox@lists.infradead.org On Wed, Nov 08, 2017 at 04:33:08PM +0100, Oleksij Rempel wrote: > this part of code is executed at least 4 times in eMMC probe sequence. > Optimizing it is reducing 20-30 msec of boot time. > > Signed-off-by: Oleksij Rempel > --- > drivers/mci/imx-esdhc.c | 14 ++++++++++---- > 1 file changed, 10 insertions(+), 4 deletions(-) > > diff --git a/drivers/mci/imx-esdhc.c b/drivers/mci/imx-esdhc.c > index 141d715c90..5c2a3a36e3 100644 > --- a/drivers/mci/imx-esdhc.c > +++ b/drivers/mci/imx-esdhc.c > @@ -95,6 +95,7 @@ struct fsl_esdhc_host { > struct device_d *dev; > struct clk *clk; > const struct esdhc_soc_data *socdata; > + u32 last_clock; > }; > > #define to_fsl_esdhc(mci) container_of(mci, struct fsl_esdhc_host, mci) > @@ -408,7 +409,7 @@ esdhc_send_cmd(struct mci_host *mci, struct mci_cmd *cmd, struct mci_data *data) > > static void set_sysctl(struct mci_host *mci, u32 clock) > { > - int div, pre_div; > + int div, pre_div, i; > struct fsl_esdhc_host *host = to_fsl_esdhc(mci); > void __iomem *regs = host->regs; > int sdhc_clk = clk_get_rate(host->clk); > @@ -453,13 +454,17 @@ static void set_sysctl(struct mci_host *mci, u32 clock) > esdhc_clrsetbits32(regs + SDHCI_CLOCK_CONTROL__TIMEOUT_CONTROL__SOFTWARE_RESET, > SYSCTL_CLOCK_MASK, clk); > > - wait_on_timeout(10 * MSECOND, > - !(esdhc_read32(regs + SDHCI_PRESENT_STATE) & PRSSTAT_SDSTB)); > + for (i = 0; i < 1000; i++) { > + if (esdhc_read32(regs + SDHCI_PRESENT_STATE) & PRSSTAT_SDSTB) > + break; > + udelay(10); > + } I hope this hunk doesn't make anything better. If yes, we have a problem. > > clk = SYSCTL_PEREN | SYSCTL_CKEN; > > esdhc_setbits32(regs + SDHCI_CLOCK_CONTROL__TIMEOUT_CONTROL__SOFTWARE_RESET, > clk); > + host->last_clock = clock; Instead of storing the desired clock I would rather store the clock we actually make from the desired clock. This way we could optimze for multiple input frequencies that result in the same actual frequency. Also please rename the variable from last_clock to cur_clock. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox