On 5 September 2016 at 17:58, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Mon, 5 Sep 2016, Ritesh Raj Sarraf wrote: > >> -----BEGIN PGP SIGNED MESSAGE----- >> Hash: SHA512 >> >> On Sun, 2016-09-04 at 15:46 -0400, Alan Stern wrote: >> > >> > This is not the problem I was discussing with Ulf. The problem was why >> > the device kept going into and out of runtime suspend every three >> > seconds. The kernel log above does not say whether this was happening. >> > One way to tell is to look at a usbmon trace (like we did before). >> >> https://people.debian.org/~rrs/tmp/usbmon.txt.gz >> >> This should have the logs you asked for, running on 4.8-rc4. > > Confirmed, the runtime suspends and resumes are still happening. > > Ulf, any insights? Alan, Ritesh, Yes, I am starting to understand more about what goes on here. Although I need help to test as I don't have the HW. As you already guessed, I suspect the problem is within the runtime PM deployment in the drivers/mmc/host/rtsx_usb_sdmmc.c. Let me start by first give you some background to how the mmc core deals with runtime PM. *) The mmc core manages most of the calls to the pm_runtime_get|put*() and pm_runtime_mark_last_busy() for the mmc host device. The gets/puts are done when the core is about to access the mmc host device, via the mmc host ops driver interface. You may search for calls to the mmc_claim|release_host() functions to find out when the gets/puts are done. **) The mmc core have also deployed runtime PM for the mmc *card* device and which has the runtime PM autosuspend feature enabled with a 3s default timeout. One important point is that the mmc card device has the mmc host device assigned as being its parent device. I guessing the reason to why you are encountering strange 3s intervals of runtime PM suspend/resume is related to this. Now, in this case, the rtsx_usb_sdmmc driver seems to need a bit of special runtime PM deployment, as the calls to pm_runtime_get|put*() also controls the power to the usb device and thus also the power to the card. I am guessing that's done via the usb device being assigned as parent for the mmc host's platform device!? By reviewing the code of the rtsx_usb_sdmmc driver, particularly how it calls pm_runtime_get|put() I am guessing those calls may not be properly deployed. Perhaps rtsx_usb_sdmmc should convert to use the usb_autopm_put|get_interface() and friends, although I didn't want to make that change at this point so instead I have cooked a patch that might fixes the behaviour. Ritesh, can you please try it out to see what happens? --- drivers/mmc/host/rtsx_usb_sdmmc.c | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/drivers/mmc/host/rtsx_usb_sdmmc.c b/drivers/mmc/host/rtsx_usb_sdmmc.c index 6c71fc9..3d6fe51 100644 --- a/drivers/mmc/host/rtsx_usb_sdmmc.c +++ b/drivers/mmc/host/rtsx_usb_sdmmc.c @@ -1138,11 +1138,6 @@ static void sdmmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios) dev_dbg(sdmmc_dev(host), "%s\n", __func__); mutex_lock(&ucr->dev_mutex); - if (rtsx_usb_card_exclusive_check(ucr, RTSX_USB_SD_CARD)) { - mutex_unlock(&ucr->dev_mutex); - return; - } - sd_set_power_mode(host, ios->power_mode); sd_set_bus_width(host, ios->bus_width); sd_set_timing(host, ios->timing, &host->ddr_mode); @@ -1336,7 +1331,7 @@ static void rtsx_usb_init_host(struct rtsx_usb_sdmmc *host) MMC_CAP_MMC_HIGHSPEED | MMC_CAP_BUS_WIDTH_TEST | MMC_CAP_UHS_SDR12 | MMC_CAP_UHS_SDR25 | MMC_CAP_UHS_SDR50 | MMC_CAP_NEEDS_POLL; - mmc->caps2 = MMC_CAP2_NO_PRESCAN_POWERUP | MMC_CAP2_FULL_PWR_CYCLE; + mmc->caps2 = MMC_CAP2_FULL_PWR_CYCLE; mmc->max_current_330 = 400; mmc->max_current_180 = 800; -- Kind regards Uffe -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
