From eb84ee977d03c53155f4141c125ad5fcb7cd0c25 Mon Sep 17 00:00:00 2001 From: Jonas Karlman Date: Sat, 27 Jan 2024 16:29:21 +0000 Subject: [PATCH] mmc: Remove alignment hole for cmdidx in struct mmc_cmd 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. Remove this alignment hole by changing cmdidx from ushort to uint. Signed-off-by: Jonas Karlman --- include/mmc.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/mmc.h b/include/mmc.h index 155a8e9f420..9a28b48f621 100644 --- a/include/mmc.h +++ b/include/mmc.h @@ -404,7 +404,7 @@ struct mmc_cid { }; struct mmc_cmd { - ushort cmdidx; + uint cmdidx; uint resp_type; uint cmdarg; uint response[4];