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Commit 3f2c7d5d authored by Helmut Grohne's avatar Helmut Grohne Committed by Ulf Hansson
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mmc: sdhci-of-arasan: Add quirk for unstable clocks 



Some controllers immediately report SDHCI_CLOCK_INT_STABLE after
enabling the clock even when the clock is not stable. When used in
conjunction with older/slower cards, this can result in:

    mmc0: error -84 whilst initialising SD card

When the stable reporting is known to be broken, we simply wait for the
maximum stabilization period.

Signed-off-by: default avatarHelmut Grohne <h.grohne@intenta.de>
Acked-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
parent 26c31228

drivers/mmc/host/sdhci-of-arasan.c

+16 −0
Original line number Diff line number Diff line
@@ -102,6 +102,9 @@ struct sdhci_arasan_data { 


/* Controller does not have CD wired and will not function normally without */

#define SDHCI_ARASAN_QUIRK_FORCE_CDTEST	BIT(0)

/* Controller immediately reports SDHCI_CLOCK_INT_STABLE after enabling the

 * internal clock even when the clock isn't stable */

#define SDHCI_ARASAN_QUIRK_CLOCK_UNSTABLE BIT(1)

};



static const struct sdhci_arasan_soc_ctl_map rk3399_soc_ctl_map = {
@@ -207,6 +210,16 @@ static void sdhci_arasan_set_clock(struct sdhci_host *host, unsigned int clock) 


	sdhci_set_clock(host, clock);



	if (sdhci_arasan->quirks & SDHCI_ARASAN_QUIRK_CLOCK_UNSTABLE)

		/*

		 * Some controllers immediately report SDHCI_CLOCK_INT_STABLE

		 * after enabling the clock even though the clock is not

		 * stable. Trying to use a clock without waiting here results

		 * in EILSEQ while detecting some older/slower cards. The

		 * chosen delay is the maximum delay from sdhci_set_clock.

		 */

		msleep(20);



	if (ctrl_phy) {

		phy_power_on(sdhci_arasan->phy);

		sdhci_arasan->is_phy_on = true;
@@ -758,6 +771,9 @@ static int sdhci_arasan_probe(struct platform_device *pdev) 
	if (of_property_read_bool(np, "xlnx,fails-without-test-cd"))

		sdhci_arasan->quirks |= SDHCI_ARASAN_QUIRK_FORCE_CDTEST;



	if (of_property_read_bool(np, "xlnx,int-clock-stable-broken"))

		sdhci_arasan->quirks |= SDHCI_ARASAN_QUIRK_CLOCK_UNSTABLE;



	pltfm_host->clk = clk_xin;



	if (of_device_is_compatible(pdev->dev.of_node,