On Tue, Oct 30, 2012 at 05:30:01PM +0800, yongd wrote: > In the current code logic, sdhci_add_host() will enable the polling > method (set MMC_CAP_NEEDS_POLL) for a removable card (MMC_CAP_ > NONREMOVABLE is not set) whose host's internal card detection method > is disabled for some reason (SDHCI_QUIRK_BROKEN_CARD_DETECTION is set). > > However, this is improper since we can have some other card detection > methods besides host internal card detection and polling method. For > example, if the card detection type is ESDHC_CD_GPIO (external gpio pin > for CD), we should keep SDHCI_QUIRK_BROKEN_CARD_DETECTION set, or host > internal card detection interrupt will still be enabled. So, here comes > the 1st change in this patch to keep SDHCI_QUIRK_BROKEN_CARD_DETECTION > set for ESDHC_CD_GPIO type. But, after the 1st change, just as above > said, sdhci_add_host() will still enable polling for such a card.This > is redundant. > This actually results in an unpleasant rather than redundant behavior. Right after this patch gets applied and before patch #3 gets applied, driver sdhci-esdhc-imx will use polling even for ESDHC_CD_GPIO case.
> On the other hand, for the card with ESDHC_CD_NONE detection type(no CD, > neither controller nor gpio, so use polling), we currently rely on > sdhci_add_host() to enable polling for us. > > Here propose the 2nd change in this patch for such an embarrassing case. Besides above, this is another sign that the patch (and series) should be better partitioned. > 1st, this patch will de-couple polling enabling with sdhci_add_host() by > doing this in host driver itself, just as some other vendors. 2nd, one > more patch will remove such improper MMC_CAP_NEEDS_POLL enabling in > sdhci_add_host(). > > Change-Id: Ia7525009d8fd188e3f0169f225e4a76ff9e94b47 Remove this, please. > Signed-off-by: yongd <yo...@marvell.com> > --- > drivers/mmc/host/sdhci-esdhc-imx.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c > b/drivers/mmc/host/sdhci-esdhc-imx.c > index effc2ac..ff201a5 100644 > --- a/drivers/mmc/host/sdhci-esdhc-imx.c > +++ b/drivers/mmc/host/sdhci-esdhc-imx.c > @@ -557,7 +557,7 @@ static int __devinit sdhci_esdhc_imx_probe(struct > platform_device *pdev) > dev_err(mmc_dev(host->mmc), "request irq error\n"); > goto no_card_detect_irq; > } > - /* fall through */ > + break; The current sdhci-esdhc-imx implementation clears flag SDHCI_QUIRK_BROKEN_CARD_DETECTION even for ESDHC_CD_GPIO case and then emulate flag SDHCI_CARD_PRESENT by reading CD gpio state in esdhc_readl_le(). Obviously, simply setting the flag for gpio case does not provide an equal behavior as before. Shawn > > case ESDHC_CD_CONTROLLER: > /* we have a working card_detect back */ > @@ -569,6 +569,7 @@ static int __devinit sdhci_esdhc_imx_probe(struct > platform_device *pdev) > break; > > case ESDHC_CD_NONE: > + host->mmc->caps = MMC_CAP_NEEDS_POLL; > break; > } > > -- > 1.7.9.5 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
