On Thu, Jan 9, 2020 at 11:48 PM Marek Vasut <ma...@denx.de> wrote: > > On 1/9/20 1:11 PM, Masahiro Yamada wrote: > > On Thu, Jan 9, 2020 at 8:16 PM Marek Vasut <ma...@denx.de> wrote: > >> > >> 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. > > > > > > I am suffering for the same problem for the uniphier platform. > > The Denali NAND patches for Linux are currently stuck on your review too.
Huh? Which patch in Linux is stuck on my review? > > 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. > > Once the Linux patches are upstream, we can just reset the NAND > controller without problems. And that's the right thing to do, sometimes > you don't want NAND to be available in Linux, and then it should be kept > in reset. The NAND reset in Linux will be available in the future version (if my patch is applied). The stable kernels are maintained in 6 years. https://www.kernel.org/category/releases.html The EOF of Linux 5.4 is set at 2021.12, but following the recent rules, it will be extended to 2026 or so. -- Best Regards Masahiro Yamada