Hello again, Jaehoon Chung wrote: > Hi Tobias, > > On 09/19/2016 07:00 PM, Tobias Jakobi wrote: >> Hey Jaehoon, >> >> >> Jaehoon Chung wrote: >>> Hi Tobias, >>> >>> On 09/19/2016 04:41 PM, Tobias Jakobi wrote: >>>> Hello Jaehoon, >>>> >>>> >>>> Jaehoon Chung wrote: >>>>> Hi Tobias, >>>>> >>>>> CC'd mmc mailing. >>>>> >>>>> On 09/19/2016 10:03 AM, Seung-Woo Kim wrote: >>>>>> Hello Jaehoon, >>>>>> >>>>>> On 2016년 09월 19일 09:32, Jaehoon Chung wrote: >>>>>>> Hi Tobias, >>>>>>> >>>>>>> On 09/16/2016 02:29 AM, Tobias Jakobi wrote: >>>>>>>> Hello everyone, >>>>>>>> >>>>>>>> I'm experiencing massive kernel log spamming by dw_mmc, the commit that >>>>>>>> causes this is the following one. >>>>>>>> >>>>>>>> 65257a0deed5aee66b4e3708944f0be62a64cabc >>>>>>>> >>>>>>>> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=65257a0deed5aee66b4e3708944f0be62a64cabc >>>>>>>> >>>>>>>> I've briefly checked the commit and I think the rationale behind >>>>>>>> removing the check is incorrect. While MMC_CLKGATE was certainly >>>>>>>> removed, runtime PM has "replaced" it (the commit >>>>>>>> 9eadcc0581a8ccaf4c2378aa1c193fb164304f1d even mentions this). >>>>>>>> >>>>>>>> This is on an Exynos4412 board, kernel is 4.8-rc6. Nothing is connected >>>>>>>> to the eMMC connector. >>>>>>> >>>>>>> Thanks for reporting this. >>>>>>> >>>>>>> Seung-Woo, Could you check your patch? I will also check this. >>>>> >>>>> Did you test after reverting this commit? or previous version is working fine? >>>> yes, reverting the commit fixes the log spamming. I'm aware though that >>>> the check is more of less broken (undefined behaviour because of >>>> bit-shifting with large values), so I have also tried the following >>>> thing: Just checking against 'div' instead of 'clock << div'. Anyway, >>>> this also works for me. >>>> >>>> >>>>> Which exynos4412 board do you use? I think it's related with "broken-cd". >>>>> (If you can share which board and dts you are using, we can check in more detail.) >>>> This is an Odroid-X2 board. >>>> >>> >>> When i have checked on odroid-u3, it's reproduced very easy. >> good to hear! I also worry that I'm the only one with these issues on >> the X2. :) >> >> Anyway, do you seen any other message on the U3 that are related to the >> eMMC. I'm asking because I have also experience some warning/error from >> the regulator subsystem: >>> Sep 15 17:19:56 chidori kernel: [ 4.976690] vddf_emmc_2.85V: voltage operation not allowed >>> Sep 15 17:19:56 chidori kernel: [ 4.995417] mmc_host mmc1: Bus speed (slot 0) = 50000000Hz (slot req 400000Hz, actual 396825HZ div = 63) >> >> I'm sending you a patch shortly which fixes the warning, but I'm not >> sure if this is the right approach. Maybe you can take a look? > > I didn't see this..what is vddf_emmc_2.85V? I can't find this anywhere. > >> >> >>>>> As you mentioned, you didn't insert the eMMC card on board. >>>>> Then it should be polling whether card is inserted/removed. (If broken-cd is set...) >>>> I can check the callstack leading to dw_mci_setup_bus() I guess. Would >>>> that should make it easier for you guys to understand where the issue >>>> originates from? >>> >>> Not need to share the callstack. Because i understood what is problem. >>> But checking 'div' instead of 'clock << div' should also have the unexpected behavior. >> Why is that? If I understood the initial problem correctly, then >> shifting with 'div' produces undefined behaviour since we don't know an >> upper bound for it. That's not the case if we just compare old and new >> divisor. > > This problem is because of "polling" method. ("broken-cd" property in device-tree) > If can't find the eMMC card, mmc_rescan_try_freq() is running four times. > Because it's looping with freqs array size in mmc_rescan(). > At that time, clock and current_speed is 400KHz..and if didn't find any cards, clock is set to 0. > After HZ, mmc_rescan is running again..and repeat above behavior. > > I didn't consider about this case. (removable case and polling method.) > > I think we can fix the below code..Could you check the below? > I have tested with exynos4412/exynos5422 boards. > If there is no issue, i will send the patch. Or if there is a problem, let me know, plz. caching the clock value (instead of just div) also seems to work, the message is just shown once. Some comments below. > diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c > index 22dacae..41306d1 100644 > --- a/drivers/mmc/host/dw_mmc.c > +++ b/drivers/mmc/host/dw_mmc.c > @@ -1112,11 +1112,12 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit) > > div = (host->bus_hz != clock) ? DIV_ROUND_UP(div, 2) : 0; > > - dev_info(&slot->mmc->class_dev, > - "Bus speed (slot %d) = %dHz (slot req %dHz, actual %dHZ div = %d)\n", > - slot->id, host->bus_hz, clock, > - div ? ((host->bus_hz / div) >> 1) : > - host->bus_hz, div); > + if (clock != slot->__clk_old || force_clkinit) > + dev_info(&slot->mmc->class_dev, > + "Bus speed (slot %d) = %dHz (slot req %dHz, actual %dHZ div = %d)\n", Put the missing comma before "div" here, i.e. "slot req %dHz, actual %dHZ, div = %d)". > + slot->id, host->bus_hz, clock, > + div ? ((host->bus_hz / div) >> 1) : > + host->bus_hz, div); > > /* disable clock */ > mci_writel(host, CLKENA, 0); > @@ -1139,6 +1140,9 @@ static void dw_mci_setup_bus(struct dw_mci_slot *slot, bool force_clkinit) > > /* inform CIU */ > mci_send_cmd(slot, sdmmc_cmd_bits, 0); > + > + /* keep the last clock value that requested from core */ "...that was requested from..." > + slot->__clk_old = clock; > } > > host->current_speed = clock; > diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h > index 9e740bc..0f12e15 100644 > --- a/drivers/mmc/host/dw_mmc.h > +++ b/drivers/mmc/host/dw_mmc.h > @@ -249,6 +249,8 @@ extern int dw_mci_resume(struct dw_mci *host); > * @queue_node: List node for placing this node in the @queue list of > * &struct dw_mci. > * @clock: Clock rate configured by set_ios(). Protected by host->lock. > + * @__clk_old: The last clock value that requested from core. Same here. With best wishes, Tobias > + * Keeping track of this helps us to avoid spamming the console. > * @flags: Random state bits associated with the slot. > * @id: Number of this slot. > * @sdio_id: Number of this slot in the SDIO interrupt registers. > @@ -263,6 +265,7 @@ struct dw_mci_slot { > struct list_head queue_node; > > unsigned int clock; > + unsigned int __clk_old; > > unsigned long flags; > #define DW_MMC_CARD_PRESENT 0 > > > Best Regards, > Jaehoon Chung > >> >> >>> If needs to fix, i want to go ahead the correct way at this time. >>> Anyway, thanks for reporting this! >> >> Also thanks, and let me know if I can test anything else. >> >> With best wishes, >> Tobias >> >> >>> Best Regards, >>> Jaehoon Chung >>> >>>> >>>> >>>>> I think it's not related with runtime PM. >>>>> >>>>> Best Regards, >>>>> Jaehoon Chung >>>> >>>> WIth best wishes, >>>> Tobias >>>> >>>> >>>> >>>> >>>>>> Ok, I will check on Exynos4412 SpC boards. >>>>>> >>>>>> By the way, to check no condition case, when I posted after v2[1], I >>>>>> checked with Exynos5422 and Exynos5433 SoC boards and they didn't show >>>>>> duplicated log, so I agreed not to check condition for logging. >>>>>> >>>>>> [1] https://patchwork.kernel.org/patch/9182469/ >>>>>> >>>>>> Best Regards, >>>>>> - Seung-Woo Kim >>>>>> >>>>>>> >>>>>>> Best Regards, >>>>>>> Jaehoon Chung >>>>>>> >>>>>>>> >>>>>>>> With best wishes, >>>>>>>> Tobias >>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>>> >>>> >>>> >>> >> >> >> >> > -- 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
