On Mon, Nov 05, 2012 at 11:34:49AM +0800, yongd wrote: > From the code logic, without SDHCI_QUIRK_BROKEN_CARD_DETECTION for ESDHC_CD_GPIO, when your card (using > GPIO detection) is removed, we can know the card's absence through the fake CARD_PRESENT flag in esdhc_readl_le(). > As a result, we can quickly return ENOMEDIUM error without command sending. Finally mmc_rescan can know the card > is removed. > Yes, that's the existing implementation, which does not require retry sending MMC_SEND_STATUS to know if card is removed. > On the other hand, with SDHCI_QUIRK_BROKEN_CARD_DETECTION for ESDHC_CD_GPIO, we will just send MMC_SEND_STATUS > command (cd_irq->sdhci_tasklet_card->mmc_recan->mmc_sd_detect->mmc_sd_alive), and we will find error since the card > is already gone. Finally, we shall also know the card is removed. > > This is really strange why the removal message shows up together with the next card inserting message. > Could u pls tell us more about what actually happened when the card is removed with my patches? Did the GPIO interrupt > happen? Was mmc_rescan() called? Did mmc_sd_detect() finally find error when it sent MMC_SEND_STATUS? What step did > the card removing procedure arrive at? Really really thanks a lot:-) > I just tracked it down a little bit. Interesting enough, it depends on how I remove the card. If I do it slowly, when the gpio interrupt triggers the MMC_SEND_STATUS query, the command can still retrieve the card status successfully. Thus driver does not detect the card removal. If I remove the card from slot quickly, I can see the removal message. With your patch series, in ESDHC_CD_GPIO case the driver will have to send MMC_SEND_STATUS (with retry) to card for knowing its presence. This is also an unpleasant behavior comparing to the existing code. I think we should query gpio state to know card presence for this case. Shawn -- 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
