Hi Marek, On 10/4/21 7:07 PM, Marek Szyprowski wrote: > Hi Jaehoon, > > On 01.10.2021 02:40, Jaehoon Chung wrote: >> On 9/27/21 8:09 PM, Krzysztof Kozlowski wrote: >>> On Mon, 13 Sept 2021 at 06:32, Christian Hewitt >>> <christianshewitt@xxxxxxxxx> wrote: >>>> https://protect2.fireeye.com/v1/url?k=6f7d4070-30e6793d-6f7ccb3f-0cc47aa8f5ba-2c8976d4b015314f&q=1&e=776d64d2-22f3-400a-a241-42af8b5f60d0&u=https%3A%2F%2Fgithub.com%2Fchewitt%2Flinux%2Fcommit%2F8a4ebfb43a394e5dc5e9fafc92a50d5e81a4f258 >>>> >>>> If I boot any recent kernel without the above patch, the emmc module on the XU4 is not detected, see: >>>> >>>> Without: >>>> >>>> [ 3.227837] mmc0: tuning execution failed: -5 >>>> [ 3.231229] mmc0: error -5 whilst initialising MMC card >>>> [ 3.536450] mmc0: tuning execution failed: -5 >>>> [ 3.539680] mmc0: error -5 whilst initialising MMC card >>>> [ 3.794056] mmc0: tuning execution failed: -5 >>>> [ 3.794212] mmc0: error -5 whilst initialising MMC card >>>> [ 4.111097] mmc0: tuning execution failed: -5 >>>> [ 4.115356] mmc0: error -5 whilst initialising MMC card >>>> [ 4.426164] mmc0: tuning execution failed: -5 >>>> [ 4.429678] mmc0: error -5 whilst initialising MMC card >>>> [ 4.756226] mmc0: tuning execution failed: -5 >>>> [ 4.760641] mmc0: error -5 whilst initialising MMC card >>>> >>>> With: >>>> >>>> [ 3.305461] mmc0: new HS400 MMC card at address 0001 >>>> [ 3.307444] mmcblk0: mmc0:0001 8GME4R 7.28 GiB >>>> [ 3.308132] mmcblk0boot0: mmc0:0001 8GME4R 4.00 MiB >>>> [ 3.309172] mmcblk0boot1: mmc0:0001 8GME4R 4.00 MiB >>>> [ 3.310255] mmcblk0rpmb: mmc0:0001 8GME4R 512 KiB, chardev (246:0) >>>> [ 3.315963] mmcblk0: p1 p2 >>>> >>>> The patch is sourced from a Linux 5.4 patchset used by several retro gaming distros for XU4 images shared in the HardKernel forums. I would be happy to submit it, but the original patch has no description in the commit message. Not being a coding developer myself I cannot explain whether it is correct or what it’s doing to add one. All I can do is confirm that it works, and is needed. SD card boot is not an issue. >>>> >>>> I’ve CC’d the original author (Marian) in case he remembers the patch and can comment. It would be good to get this upstream. >>> The patch might have sense but would require describing conditions - >>> what MMC input and output clock settings work and which do not work. >>> Also someone would need to test other Exynos5422 boards and other >>> Exynos with HS200 and HS400 support (Exynos5433, Exynos7). I think >>> this should not affect SD cards. >> >> Thanks for adding me. >> I didn't see XU4 booting fail with linux-5.15-rc1 kernel. >> >> [ 4.561934] mmc1: new HS400 MMC card at address 0001 >> [ 4.572401] mmcblk1: mmc1:0001 SDW16G 14.7 GiB >> [ 4.602555] mmcblk1: p1 p2 p3 p4 < p5 p6 p7 > >> [ 4.623201] mmcblk1boot0: mmc1:0001 SDW16G 4.00 MiB >> [ 4.640465] mmcblk1boot1: mmc1:0001 SDW16G 4.00 MiB >> >> Which kernel version did you use? > > I came across this patch some time ago, but also didn't manage to > reproduce the issue - in my case eMMC was always detected properly. It > might be related to particular version or series of the eMMC modules. > > I've just checked that patch on XU3, XU4, PeachPi and TM2e boards. All > are working properly with it. > > I've also tried to benchmark the impact of that change and in some case > it causes some performance degradation. Thanks for checking them. I had also suspected that this problem is producing according to eMMC modules. (Chritian's eMMC is different with mine.) > > The main difference is clock configuration. Before this patch (XU4): > > # dmesg | grep mmc0 > mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 400000Hz, > actual 396825HZ div = 63) > mmc_host mmc0: Bus speed (slot 0) = 200000000Hz (slot req 200000000Hz, > actual 200000000HZ div = 0) > mmc_host mmc0: Bus speed (slot 0) = 50000000Hz (slot req 52000000Hz, > actual 50000000HZ div = 0) > mmc_host mmc0: Bus speed (slot 0) = 400000000Hz (slot req 200000000Hz, > actual 200000000HZ div = 1) > mmc0: new HS400 MMC card at address 0001 > mmcblk0: mmc0:0001 SDW16G 14.7 GiB > mmcblk0boot0: mmc0:0001 SDW16G 4.00 MiB > mmcblk0boot1: mmc0:0001 SDW16G 4.00 MiB > mmcblk0rpmb: mmc0:0001 SDW16G 4.00 MiB, chardev (245:0) > > After applying the patch (mmc device number is random depending on the > boot): > > # dmesg | grep mmc1 > [ 3.619177] mmc_host mmc1: Bus speed (slot 0) = 50000000Hz (slot req > 400000Hz, actual 396825HZ div = 63) > [ 4.057167] mmc_host mmc1: Bus speed (slot 0) = 200000000Hz (slot req > 200000000Hz, actual 200000000HZ div = 0) > [ 4.070040] mmc_host mmc1: Bus speed (slot 0) = 50000000Hz (slot req > 52000000Hz, actual 50000000HZ div = 0) > [ 4.089028] mmc_host mmc1: Bus speed (slot 0) = 266666666Hz (slot req > 200000000Hz, actual 133333333HZ div = 1) > [ 4.102296] mmc1: new HS400 MMC card at address 0001 > [ 4.119072] mmcblk1: mmc1:0001 SDW16G 14.7 GiB > [ 4.173507] mmcblk1boot0: mmc1:0001 SDW16G 4.00 MiB > [ 4.196210] mmcblk1boot1: mmc1:0001 SDW16G 4.00 MiB > [ 4.215163] mmcblk1rpmb: mmc1:0001 SDW16G 4.00 MiB, chardev (245:0) > > The performance has been measured with: > > # dd if=/dev/mmcblk1p6 of=/dev/null bs=128k > 31944+0 records in > 31944+0 records out > 4186963968 bytes (4.2 GB) copied, 36.6981 s, 114 MB/s > > Results (XU4 board): > > exynos_defconfig: 145 MB/s (before) vs 114 MB/s (after) > exynos_defconfig + all devfreqs set to performance: 146 MB/s vs 115 MB/s > exynos_defconfig + cpufreq & all devfreqs set to performance: 154 MB/s > vs 139 MB/s > exynos_defconfig + CONFIG_ARM_EXYNOS_BUS_DEVFREQ disabled: 130 MB/s vs > 108 MB/s > exynos_defconfig + CONFIG_CPUFREQ_DT disabled: 69 MB/s (no impact) > exynos_defconfig + CONFIG_ARM_EXYNOS_BUS_DEVFREQ & CONFIG_CPUFREQ_DT: 66 > MB/s (no impact) > > > Maybe some other clock configuration (I mean the rate of the top-level > clocks or even PLLS) will solve the issue without degrading the > performance, but it is hard to judge that without reproducing the issue. I'm checking this problem in more detail since today. I don't have all eMMC modules to connect on XU3/4. So as you mentioned, it's difficult to check without reproducing the issue. I'm trying to find eMMC module to reproduce this issue in my office. Best Regards, Jaehoon Chung > > > Best regards >
