2021-01-18 11:36:11

by Ahmad Fatoum

[permalink] [raw]
Subject: [PATCH v2] clk: imx6q: demote warning about pre-boot ldb_di_clk reparenting

Since 5d283b083800 ("clk: imx6: Fix procedure to switch the parent
of LDB_DI_CLK"), the clock driver warns if ldb_di\d_sel is changed
from reset value on system boot. This warning is printed even if
the bootloader (or a previous kernel that did kexec) followed the
correct procedure for glitch-free reparenting.

As such systems are doing everything correctly, a warning is too
harsh. Demote to a notice, so users are still alerted, but without
cluttering a loglevel=5 boot.

While at it, add the words "possible glitch" into the log message, to
make it more user-friendly.

Signed-off-by: Ahmad Fatoum <[email protected]>
---
Cc: Fabio Estevam <[email protected]>

v1 -> v2:
- added "possile glitch" to error message to make more useful
(Stephen)
---
drivers/clk/imx/clk-imx6q.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/imx/clk-imx6q.c b/drivers/clk/imx/clk-imx6q.c
index b2ff187cedab..521d6136d22c 100644
--- a/drivers/clk/imx/clk-imx6q.c
+++ b/drivers/clk/imx/clk-imx6q.c
@@ -338,10 +338,10 @@ static void init_ldb_clks(struct device_node *np, void __iomem *ccm_base)
of_assigned_ldb_sels(np, &sel[0][3], &sel[1][3]);

for (i = 0; i < 2; i++) {
- /* Warn if a glitch might have been introduced already */
+ /* Print a notice if a glitch might have been introduced already */
if (sel[i][0] != 3) {
- pr_warn("ccm: ldb_di%d_sel already changed from reset value: %d\n",
- i, sel[i][0]);
+ pr_notice("ccm: possible glitch: ldb_di%d_sel already changed from reset value: %d\n",
+ i, sel[i][0]);
}

if (sel[i][0] == sel[i][3])
--
2.30.0


2021-01-19 05:43:51

by Fabio Estevam

[permalink] [raw]
Subject: Re: [PATCH v2] clk: imx6q: demote warning about pre-boot ldb_di_clk reparenting

Hi Ahmad,

On Mon, Jan 18, 2021 at 8:30 AM Ahmad Fatoum <[email protected]> wrote:
>
> Since 5d283b083800 ("clk: imx6: Fix procedure to switch the parent
> of LDB_DI_CLK"), the clock driver warns if ldb_di\d_sel is changed
> from reset value on system boot. This warning is printed even if
> the bootloader (or a previous kernel that did kexec) followed the
> correct procedure for glitch-free reparenting.
>
> As such systems are doing everything correctly, a warning is too
> harsh. Demote to a notice, so users are still alerted, but without
> cluttering a loglevel=5 boot.
>
> While at it, add the words "possible glitch" into the log message, to
> make it more user-friendly.
>
> Signed-off-by: Ahmad Fatoum <[email protected]>

Reviewed-by: Fabio Estevam <[email protected]>