On Sat Sep 30, 2023 at 1:06 AM CEST, Jonas Karlman wrote: > The alignment hole caused by cmdidx in struct mmc_cmd cause strange > issues together with the peephole2 optimization on Amlogic SoCs. > Following was observed while working on SPL support for Amlogic SoCs. > > sd_get_capabilities() normally issue a CMD55 followed by a CMD51. > However, on at least Amlogic S905 (Cortex-A53) and S905X3 (Cortex-A55), > CMD55 was instead followed by CMD8 (and a few reties) in SPL. > > Code from the call site: > > cmd.cmdidx = SD_CMD_APP_SEND_SCR; // 51 > ... > data.blocksize = 8; > ... > err = mmc_send_cmd_retry(mmc, &cmd, &data, 3); > > Running the code with MMC_TRACE enabled shows: > > CMD_SEND:55 > ARG 0x50480000 > MMC_RSP_R1,5,6,7 0x00000920 > CMD_SEND:8 > ARG 0x00000000 > RET -110 > > Removing the alignment hole by changing cmdidx from ushort to uint or > building with -fno-peephole2 flag seem to resolve this issue. > > CMD_SEND:55 > ARG 0x50480000 > MMC_RSP_R1,5,6,7 0x00000920 > CMD_SEND:51 > ARG 0x00000000 > MMC_RSP_R1,5,6,7 0x00000920 > > Same issue was observed building U-Boot with gcc 8-13. Please advise on > how to best work around this possible gcc optimization bug. > > Signed-off-by: Jonas Karlman <[email protected]>
I'll try reproducing this. I'm using this: https://git.vitali64.duckdns.org/misc/u-boot-kii-pro.git (branch: wip/spl, known to boot on S905/GXBB) For reference, I'm using this version of aarch64 gcc (from the Arch Linux repos): $ aarch64-linux-gnu-gcc --version aarch64-linux-gnu-gcc (GCC) 13.1.0 Copyright (C) 2023 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. And this version of (host) gcc: $ gcc --version gcc (GCC) 13.1.1 20230429 Copyright (C) 2023 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. Cheers.
