From: Oleksij Rempel <o.rempel@pengutronix.de>
To: barebox@lists.infradead.org
Cc: Oleksij Rempel <o.rempel@pengutronix.de>
Subject: [PATCH v1] i.MX: esdhc: optimize set_ios path
Date: Wed, 8 Nov 2017 16:33:08 +0100 [thread overview]
Message-ID: <20171108153308.17351-1-o.rempel@pengutronix.de> (raw)
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 <o.rempel@pengutronix.de>
---
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);
+ }
clk = SYSCTL_PEREN | SYSCTL_CKEN;
esdhc_setbits32(regs + SDHCI_CLOCK_CONTROL__TIMEOUT_CONTROL__SOFTWARE_RESET,
clk);
+ host->last_clock = clock;
}
static void esdhc_set_ios(struct mci_host *mci, struct mci_ios *ios)
@@ -468,7 +473,8 @@ static void esdhc_set_ios(struct mci_host *mci, struct mci_ios *ios)
void __iomem *regs = host->regs;
/* Set the clock speed */
- set_sysctl(mci, ios->clock);
+ if (host->last_clock != ios->clock)
+ set_sysctl(mci, ios->clock);
/* Set the bus width */
esdhc_clrbits32(regs + SDHCI_HOST_CONTROL__POWER_CONTROL__BLOCK_GAP_CONTROL,
--
2.11.0
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next reply other threads:[~2017-11-08 15:33 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-08 15:33 Oleksij Rempel [this message]
2017-11-09 10:04 ` Sascha Hauer
2017-11-09 17:08 ` Oleksij Rempel
2017-11-09 20:13 ` Sascha Hauer
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