On Thu, Jan 9, 2020 at 8:16 PM Marek Vasut marex@denx.de wrote:
On 1/9/20 12:04 PM, Masahiro Yamada wrote:
On Thu, Jan 9, 2020 at 7:08 PM Marek Vasut marex@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 marex@denx.de Cc: Masahiro Yamada yamada.masahiro@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.
I am suffering for the same problem for the uniphier platform.
The reset driver support for Linux will never be back-ported. So, it will continue to be a problem for Linux v4.19, v5.4, etc.
reset_release_bulk() should go away.