On 11/23/2015 07:11 PM, Jaehoon Chung wrote: > Dear, Jorge. > > On 11/24/2015 02:29 AM, Jorge Ramirez-Ortiz wrote: >> On 11/23/2015 11:57 AM, Doug Anderson wrote: >>> Jorge, >>> >>> On Mon, Nov 23, 2015 at 6:10 AM, Jorge Ramirez-Ortiz >>> <jorge.ramirez-ortiz@xxxxxxxxxx> wrote: >>>> Doug/Jaehoon, >>>> >>>> Were there any follow ups to this thread [1] from March 30, 2015? >>>> We are seeing HLE errors on 3.18 and we are trying to determine if a solution >>>> was ever delivered. >>>> On inspection, I can't find anything specific in recent kernels that address >>>> this particular issue (was the actual root cause identified?) >>>> >>>> I put together a possible work-around that avoids the HLE storm from occurring >>>> for this specific SoC [2]. >>>> However we'd rather not merge this -or any other similar fix- if there is a >>>> generic solution already that we can pick up from mainline. >>> Nothing landed that I'm aware of. Are you on SDIO, SD or eMMC? >>> Trying to do UHS? >> SD even without UHS (yet, that is coming now) > If you want to use the upper mode than UHS-DDR50 for SD-card, you need to apply the below patch. ACK > > https://patchwork.kernel.org/patch/7456121/ > > Actually, this is not relevant to HLE error. > > When sd-card is inserted/removed quickly, then sometime dwmmc controller is occurred the HLE error. > (Now, i can't see HLE error.) > So i had applied the some reset processing at my official repository.(It's not generic solution.) Thanks, I'll have a look now. I believe this to be your official repo: https://github.com/jh80chung/dw-mmc Please let me know if it is not. > >>> I know that this patch mattered for me for UHS: >>> >>> 7c5209c315ea mmc: core: Increase delay for voltage to stabilize from >>> 3.3V to 1.8V >>> >>> >>> Also important for UHS (for at least some folks) were patches like: >>> >>> 9c85f37a2984 mmc: core: Add mmc_regulator_set_vqmmc() >>> >>> ...that attempted to get voltages more proper... >> ack >> >>> >>> In the ChromeOS tree we did just land treating HLE errors as data and >>> cmd errors <https://patchwork.kernel.org/patch/5978711/>. It's not >>> wonderful but it's better than letting an interrupt go off forever... >> Yes I did try this patch on 3.18 but it didn't seem to be enough for us. >> Even though it would prevent the interrupt storm from flooding the kernel, once >> the event triggered and the interrupt was handled no more card >> insertions/ejections would be detected. > If HLE error will be reproduce with the generic sequence, I think we can find the generic solution. > So could you explain to me in more detail? If i can reproduce with v3.18, i will try to test it. > Your case will be helpful to me for solving the HLE error. Yes, the issue is relatively easy to reproduce. On this platform: https://www.96boards.org/products/ce/hikey/ Using either debian [1] or android [2] releases and the latest UEFI [3] [1] https://builds.96boards.org/snapshots/hikey/linaro/debian/379/ [2] https://builds.96boards.org/snapshots/hikey/linaro/aosp/197/ [3] https://builds.96boards.org/snapshots/hikey/linaro/uefi/89/ The kernel tree between android and debian is shared [4]. We are using the "hikey" branch (v3.18) [4] https://github.com/96boards/linux For my tests and to be able to handed the interrupt storm and monitor the registers while it happens, I patched the kernel with a Xenomai [5] co-kernel. This is my kernel tree [6] [5] http://xenomai.org/ [6] http://git.xenomai.org/ipipe-jro.git/log/?h=hikey To reproduce the problem all it was required was to insert/remove the SD card rapidly until it triggers this condition: [ 229.974525] dwmmc_k3 f723e000.dwmmc1: Busy; trying anyway When it triggered, and after patching the interrupt handler with some debug info to show the distance between interrupts and the content of the MINTSTS register, I could see the following: mci_isr: 0x1000, 3333 ns mci_isr: 0x1000, 3334 ns mci_isr: 0x1000, 3333 ns mci_isr: 0x1000, 3334 ns mci_isr: 0x1000, 3333 ns mci_isr: 0x1000, 2500 ns mci_isr: 0x1000, 3334 ns mci_isr: 0x1000, 2500 ns mci_isr: 0x1000, 3333 ns mci_isr: 0x1000, 3334 ns mci_isr: 0x1000, 3334 ns mci_isr: 0x1000, 3333 ns mci_isr: 0x1000, 3334 ns mci_isr: 0x1000, 2500 ns mci_isr: 0x1000, 3334 ns [...] Notice that since the Xenomai co-kernel runs with a higher priority than the Linux kernel, I was able to output this information to the console. I put together a fix based on this commit from Doug; mmc: dw_mmc: Don't start commands while busy https://lkml.org/lkml/2015/2/20/508 In Doug's commit, we would delay sending a command until the SDMCC_STATUS_BUSY cleared. However if it never cleared, we'd go ahead and submit the command anyway. I believe this is what was causing the HLE to be raised. In order to prevent that from happening, I think we should abort the operation completely. My "extension" for the Hikey platform looks like this: https://github.com/96boards/linux/commit/fe8d7f714d420121cec460e69f6529044a2cb6d It could be made generic or the fix could have some other form of course. I was only targeting the Hikey platform when I wrote this hoping that it would have been fixed upstream. Having said all of this, I am not sure what would cause the host status to remain busy for so long (which is Ulf's biggest concern) I also tried increasing some of the timers that wait for the voltages to ramp up after power on but it didnt make any difference. I captured most of the information above under this bug for reference. https://bugs.96boards.org/show_bug.cgi?id=175 -- 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
