Hi Greg, > -----Original Message----- > From: Eugeniy Paltsev <Eugeniy.Paltsev@xxxxxxxxxxxx> > Sent: Thursday, February 14, 2019 6:08 PM > To: linux-snps-arc@xxxxxxxxxxxxxxxxxxx; Vineet Gupta <vgupta@xxxxxxxxxxxx> > Cc: linux-kernel@xxxxxxxxxxxxxxx; Alexey Brodkin <abrodkin@xxxxxxxxxxxx>; Corentin Labbe > <clabbe@xxxxxxxxxxxx>; khilman@xxxxxxxxxxxx; Eugeniy Paltsev <Eugeniy.Paltsev@xxxxxxxxxxxx> > Subject: [PATCH v2 2/2] ARC: enable uboot support unconditionally > > After reworking U-boot args handling code and adding paranoid > arguments check we can eliminate CONFIG_ARC_UBOOT_SUPPORT and > enable uboot support unconditionally. > > For JTAG case we can assume that core registers will come up > reset value of 0 or in worst case we rely on user passing > '-on=clear_regs' to Metaware debugger. > > Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@xxxxxxxxxxxx> May we have this one back-ported to linux-4.19.y? It was initially applied to Linus' tree during 5.0 development cycle [1] but was never back-ported. Now w/o that patch in KernelCI we see boot failure on ARC HSDK board [2] as opposed to normally working later kernel versions. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=493a2f812446e92bcb1e69a77381b4d39808d730 [2] https://storage.kernelci.org/stable/linux-4.19.y/v4.19.59/arc/hsdk_defconfig/gcc-8/lab-baylibre/boot-hsdk.txt Below is that same patch but rebased on linux-4.19 as in its pristine form it won't apply due to offset of one of hunks. -Alexey ------------------------------------>8-------------------------------- >From 3e565355f6a2d1a82bc9ecd47a46d1fa3c0cd2c1 Mon Sep 17 00:00:00 2001 From: Eugeniy Paltsev <Eugeniy.Paltsev@xxxxxxxxxxxx> Date: Thu, 14 Feb 2019 18:07:45 +0300 Subject: [PATCH] ARC: enable uboot support unconditionally After reworking U-boot args handling code and adding paranoid arguments check we can eliminate CONFIG_ARC_UBOOT_SUPPORT and enable uboot support unconditionally. For JTAG case we can assume that core registers will come up reset value of 0 or in worst case we rely on user passing '-on=clear_regs' to Metaware debugger. Cc: stable@xxxxxxxxxxxxxxx Tested-by: Corentin LABBE <clabbe@xxxxxxxxxxxx> Signed-off-by: Eugeniy Paltsev <Eugeniy.Paltsev@xxxxxxxxxxxx> Signed-off-by: Vineet Gupta <vgupta@xxxxxxxxxxxx> --- arch/arc/Kconfig | 13 ------------- arch/arc/configs/nps_defconfig | 1 - arch/arc/configs/vdk_hs38_defconfig | 1 - arch/arc/configs/vdk_hs38_smp_defconfig | 2 -- arch/arc/kernel/head.S | 2 -- arch/arc/kernel/setup.c | 2 -- 6 files changed, 21 deletions(-) diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig index 85eb7fc2e241..97b45fe8f0c2 100644 --- a/arch/arc/Kconfig +++ b/arch/arc/Kconfig @@ -199,7 +199,6 @@ config NR_CPUS config ARC_SMP_HALT_ON_RESET bool "Enable Halt-on-reset boot mode" - default y if ARC_UBOOT_SUPPORT help In SMP configuration cores can be configured as Halt-on-reset or they could all start at same time. For Halt-on-reset, non @@ -538,18 +537,6 @@ config ARC_DBG_TLB_PARANOIA endif -config ARC_UBOOT_SUPPORT - bool "Support uboot arg Handling" - default n - help - ARC Linux by default checks for uboot provided args as pointers to - external cmdline or DTB. This however breaks in absence of uboot, - when booting from Metaware debugger directly, as the registers are - not zeroed out on reset by mdb and/or ARCv2 based cores. The bogus - registers look like uboot args to kernel which then chokes. - So only enable the uboot arg checking/processing if users are sure - of uboot being in play. - config ARC_BUILTIN_DTB_NAME string "Built in DTB" help diff --git a/arch/arc/configs/nps_defconfig b/arch/arc/configs/nps_defconfig index 6e84060e7c90..621f59407d76 100644 --- a/arch/arc/configs/nps_defconfig +++ b/arch/arc/configs/nps_defconfig @@ -31,7 +31,6 @@ CONFIG_ARC_CACHE_LINE_SHIFT=5 # CONFIG_ARC_HAS_LLSC is not set CONFIG_ARC_KVADDR_SIZE=402 CONFIG_ARC_EMUL_UNALIGNED=y -CONFIG_ARC_UBOOT_SUPPORT=y CONFIG_PREEMPT=y CONFIG_NET=y CONFIG_UNIX=y diff --git a/arch/arc/configs/vdk_hs38_defconfig b/arch/arc/configs/vdk_hs38_defconfig index 1e59a2e9c602..e447ace6fa1c 100644 --- a/arch/arc/configs/vdk_hs38_defconfig +++ b/arch/arc/configs/vdk_hs38_defconfig @@ -13,7 +13,6 @@ CONFIG_PARTITION_ADVANCED=y CONFIG_ARC_PLAT_AXS10X=y CONFIG_AXS103=y CONFIG_ISA_ARCV2=y -CONFIG_ARC_UBOOT_SUPPORT=y CONFIG_ARC_BUILTIN_DTB_NAME="vdk_hs38" CONFIG_PREEMPT=y CONFIG_NET=y diff --git a/arch/arc/configs/vdk_hs38_smp_defconfig b/arch/arc/configs/vdk_hs38_smp_defconfig index b5c3f6c54b03..c82cdb10aaf4 100644 --- a/arch/arc/configs/vdk_hs38_smp_defconfig +++ b/arch/arc/configs/vdk_hs38_smp_defconfig @@ -15,8 +15,6 @@ CONFIG_AXS103=y CONFIG_ISA_ARCV2=y CONFIG_SMP=y # CONFIG_ARC_TIMERS_64BIT is not set -# CONFIG_ARC_SMP_HALT_ON_RESET is not set -CONFIG_ARC_UBOOT_SUPPORT=y CONFIG_ARC_BUILTIN_DTB_NAME="vdk_hs38_smp" CONFIG_PREEMPT=y CONFIG_NET=y diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S index 208bf2c9e7b0..a72bbda2f7aa 100644 --- a/arch/arc/kernel/head.S +++ b/arch/arc/kernel/head.S @@ -100,7 +100,6 @@ ENTRY(stext) st.ab 0, [r5, 4] 1: -#ifdef CONFIG_ARC_UBOOT_SUPPORT ; Uboot - kernel ABI ; r0 = [0] No uboot interaction, [1] cmdline in r2, [2] DTB in r2 ; r1 = magic number (always zero as of now) @@ -109,7 +108,6 @@ ENTRY(stext) st r0, [@uboot_tag] st r1, [@uboot_magic] st r2, [@uboot_arg] -#endif ; setup "current" tsk and optionally cache it in dedicated r25 mov r9, @init_task diff --git a/arch/arc/kernel/setup.c b/arch/arc/kernel/setup.c index a1218937abd6..89c97dcfa360 100644 --- a/arch/arc/kernel/setup.c +++ b/arch/arc/kernel/setup.c @@ -493,7 +493,6 @@ void __init handle_uboot_args(void) bool use_embedded_dtb = true; bool append_cmdline = false; -#ifdef CONFIG_ARC_UBOOT_SUPPORT /* check that we know this tag */ if (uboot_tag != UBOOT_TAG_NONE && uboot_tag != UBOOT_TAG_CMDLINE && @@ -525,7 +524,6 @@ void __init handle_uboot_args(void) append_cmdline = true; ignore_uboot_args: -#endif if (use_embedded_dtb) { machine_desc = setup_machine_fdt(__dtb_start); -- 2.16.2
