On 1/9/20 12:04 PM, Masahiro Yamada wrote: > On Thu, Jan 9, 2020 at 7:08 PM Marek Vasut <ma...@denx.de> wrote: >> >> Legacy kernel versions for SoCFPGA may not implement proper reset >> handling. Apply the same approach as SoCFPGA reset driver, check >> environment variable "socfpga_legacy_reset_compat", and if it is >> set, do not reset the IP before booting Linux. This way, even the >> older kernel versions can be booted by up to date U-Boot. >> >> Signed-off-by: Marek Vasut <ma...@denx.de> >> Cc: Masahiro Yamada <yamada.masah...@socionext.com> >> --- >> drivers/mtd/nand/raw/denali_dt.c | 12 ++++++++++++ >> 1 file changed, 12 insertions(+) >> >> diff --git a/drivers/mtd/nand/raw/denali_dt.c >> b/drivers/mtd/nand/raw/denali_dt.c >> index 2c9e249ab6..d35f2a3543 100644 >> --- a/drivers/mtd/nand/raw/denali_dt.c >> +++ b/drivers/mtd/nand/raw/denali_dt.c >> @@ -148,6 +148,18 @@ static int denali_dt_remove(struct udevice *dev) >> { >> struct denali_nand_info *denali = dev_get_priv(dev); >> >> +#if CONFIG_IS_ENABLED(ARCH_SOCFPGA) >> + /* >> + * Legacy kernel versions do not implement proper reset handling on >> + * SoCFPGA. To let those older kernel versions work, reuse the same >> + * approach as the SoCFPGA reset driver does -- check environment >> + * variable socfpga_legacy_reset_compat and avoid resetting the IP >> + * before booting the kernel if it is set to 1. >> + */ >> + if (env_get_ulong("socfpga_legacy_reset_compat", 10, 0)) >> + return 0; >> +#endif >> + >> return reset_release_bulk(&denali->resets); >> } > > > Why don't you simply remove reset_release_bulk() ?
Because once mainline has proper reset handling, this can be used only for legacy kernel versions.