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.
