[v2] riscv: always honor the CONFIG_CMDLINE_FORCE when parsing dtb

Commit Message

Wenting Zhang July 8, 2022, 8:38 p.m. UTC

When CONFIG_CMDLINE_FORCE is enabled, cmdline provided by
CONFIG_CMDLINE are always used. This allows CONFIG_CMDLINE to be
used regardless of the result of device tree scanning.

This especially fixes the case where a device tree without the
chosen node is supplied to the kernel. In such cases,
early_init_dt_scan would return true. But inside
early_init_dt_scan_chosen, the cmdline won't be updated as there
is no chosen node in the device tree. As a result, CONFIG_CMDLINE
is not copied into boot_command_line even if CONFIG_CMDLINE_FORCE
is enabled. This commit allows properly update boot_command_line
in this situation.

Fixes: 8fd6e05c7463 ("arch: riscv: support kernel command line forcing when no DTB passed")
Signed-off-by: Wenting Zhang <[e-mail]>
---

ChangeLog:

v2: Add fixes in commit message; fix code style

 arch/riscv/kernel/setup.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Björn Töpel Oct. 10, 2022, 3:10 p.m. UTC | #1

Wenting Zhang <[e-mail]> writes:

> When CONFIG_CMDLINE_FORCE is enabled, cmdline provided by
> CONFIG_CMDLINE are always used. This allows CONFIG_CMDLINE to be
> used regardless of the result of device tree scanning.
>
> This especially fixes the case where a device tree without the
> chosen node is supplied to the kernel. In such cases,
> early_init_dt_scan would return true. But inside
> early_init_dt_scan_chosen, the cmdline won't be updated as there
> is no chosen node in the device tree. As a result, CONFIG_CMDLINE
> is not copied into boot_command_line even if CONFIG_CMDLINE_FORCE
> is enabled. This commit allows properly update boot_command_line
> in this situation.
>
> Fixes: 8fd6e05c7463 ("arch: riscv: support kernel command line forcing when no DTB passed")
> Signed-off-by: Wenting Zhang <[e-mail]>

Reviewed-by: Björn Töpel <[e-mail]>

Conor Dooley Oct. 11, 2022, 1:03 p.m. UTC | #2

On Mon, Oct 10, 2022 at 05:10:33PM +0200, Björn Töpel wrote:
> Wenting Zhang <[e-mail]> writes:
> 
> > When CONFIG_CMDLINE_FORCE is enabled, cmdline provided by
> > CONFIG_CMDLINE are always used. This allows CONFIG_CMDLINE to be
> > used regardless of the result of device tree scanning.
> >
> > This especially fixes the case where a device tree without the
> > chosen node is supplied to the kernel. In such cases,
> > early_init_dt_scan would return true. But inside
> > early_init_dt_scan_chosen, the cmdline won't be updated as there
> > is no chosen node in the device tree. As a result, CONFIG_CMDLINE
> > is not copied into boot_command_line even if CONFIG_CMDLINE_FORCE
> > is enabled. This commit allows properly update boot_command_line
> > in this situation.
> >
> > Fixes: 8fd6e05c7463 ("arch: riscv: support kernel command line forcing when no DTB passed")
> > Signed-off-by: Wenting Zhang <[e-mail]>
> 
> Reviewed-by: Björn Töpel <[e-mail]>

I noticed that the version of this patch that I had left un-archived in
patchwork was not the correct one. I then realised I gave a "LGTM" type
thing in reponse to the v1, about the v2 but nothing on v2 itself.

Reviewed-by: Conor Dooley <[e-mail]>

Thanks,
Conor.

Patch

diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
index f0f36a4a0e9b..061cf8db3156 100644
--- a/arch/riscv/kernel/setup.c
+++ b/arch/riscv/kernel/setup.c
@@ -251,10 +251,10 @@  static void __init parse_dtb(void)
 			pr_info("Machine model: %s\n", name);
 			dump_stack_set_arch_desc("%s (DT)", name);
 		}
-		return;
+	} else {
+		pr_err("No DTB passed to the kernel\n");
 	}
 
-	pr_err("No DTB passed to the kernel\n");
 #ifdef CONFIG_CMDLINE_FORCE
 	strscpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
 	pr_info("Forcing kernel command line to: %s\n", boot_command_line);