Shawn, Thanks for your comment. And sorry for my so late due to illness:-) SDHCI_QUIRK_BROKEN_CARD_DETECTION is used for notifying we don't use the host internal card detection method so that we don't need enable/disable those relevant interrupt bits of host(sdhci_set_card_detection in sdhci.c). And as I double-checked the latest kernel code, actually sdhci-esdhc-imx sets this flag by default, and then will clear it only when the detection type is ESDHC_CD_CONTROLLER. So this aligns with my understanding. What I want to do is that 1st we shall set MMC_CAP_NEEDS_POLL by our host driver itself and 2nd remove the improper logic in sdhci_add_host() . How do u think? Thanks. ________________________________________ From: Shawn Guo [shawn.guo@xxxxxxxxxx] Sent: Sunday, October 07, 2012 22:06 To: Yong Ding Cc: Chris Ball; Anton Vorontsov; Marek Szyprowski; Wolfram Sang; Daniel Drake; Sascha Hauer; Wilson Callan; Ben Dooks; Zhangfei Gao; Kevin Liu; Jialing Fu; linux-mmc@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx Subject: Re: [PATCH 1/3] mmc: esdhc: enable polling to detect card by itself On Fri, Sep 28, 2012 at 06:28:31PM +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 will keep SDHCI_QUIRK_BROKEN_CARD_DETECTION set. This is right. > But, just as above said, sdhci_add_host() will also enable polling for such > a card. This is redundant. > At least for sdhci-esdhc-imx, SDHCI_QUIRK_BROKEN_CARD_DETECTION will be set only when neither ESDHC_CD_GPIO nor ESDHC_CD_CONTROLLER works. Shawn > 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 proposed a solution for such an embarrassing case. 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 > Signed-off-by: yongd <yongd@xxxxxxxxxxx> > --- > drivers/mmc/host/sdhci-esdhc-imx.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c > index e23f813..f70079c 100644 > --- a/drivers/mmc/host/sdhci-esdhc-imx.c > +++ b/drivers/mmc/host/sdhci-esdhc-imx.c > @@ -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-mmc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
