Re: [RESEND PATCH v4] clk: stm32f4: fix post divisor setup for I2S/SAI PLLs

From: Dario Binacchi
Date: Sun Aug 01 2021 - 15:37:15 EST

Next message: Liam Beguin: "[PATCH v7 00/13] iio: afe: add temperature rescaling support"
Previous message: Pavel Skripkin: "Re: [PATCH] net: pegasus: fix uninit-value in get_interrupt_interval"
In reply to: Dillon Hua: "Re: [RESEND PATCH v4] clk: stm32f4: fix post divisor setup for I2S/SAI PLLs"
Next in thread: Stephen Boyd: "Re: [RESEND PATCH v4] clk: stm32f4: fix post divisor setup for I2S/SAI PLLs"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

Hi Dillon and Stephen,

> Il 01/08/2021 16:56 Dillon Hua <dillonhua@xxxxxxxxx> ha scritto:
>
>
> Hi Dario
>
> On Thu, Jul 29, 2021 at 6:03 PM Dario Binacchi <dariobin@xxxxxxxxx> wrote:
> >
> > Hi Dillon,
> >
> > > Il 28/07/2021 12:03 Dillon Hua <dillonhua@xxxxxxxxx> ha scritto:
> > >
> > >
> > > Hi Dario,
> > >
> > > I have a similar patch [1] submitted last year.
> > > Unfortunately, it did not get accepted by the maintainer.
> > >
> > > Just a reminder here for you, should remove
> > >
> > > { STM32F4_RCC_APB2ENR, 26, "ltdc", "apb2_div" },
> >
> > Thank you for your suggestion.
> > While testing the patch on the stm32f469-disco board I didn't
> > notice the white screen issue. I'll try to run the tests again.
> > I will let you know.
>
> Thanks, be sure clk_ignore_unused is not set from the kernel cmdline
> at your test.

This is the kernel command line of my tests:
console=ttySTM0,115200 root=/dev/mmcblk0p2 rw rootfstype=ext2 rootwait earlyprintk consoleblank=0 ignore_loglevel

In previous emails I forgot to mention that the patch was in turn applied to a buildroot patch [1] and
acked by Christophe Priouzeau of ST microelectronics. However, I rerun the tests and did not notice
anything strange.

I then enabled CONFIG_VT, CONFIG_FRAMEBUFFER_CONSOLE and CONFIG_LOGO, and indedd the command
'echo Dario >/dev/tty0' prints my name on the display only by removing
{STM32F4_RCC_APB2ENR, 26, "ltdc", "apb2_div"}.

As said in a previous email to Stephen, the patch I submitted fixes commit 517633ef630e
("clk: stm32f4: Add post divisor for I2S & SAI PLLs"), so IMHO it should not be dropped from the tree.
What Dillon suggested should instead be fixed by another patch.

Waiting for your opinion,
Thanks and regards,
Dario

[1] https://patchwork.ozlabs.org/project/buildroot/patch/20210716164243.17988-1-dariobin@xxxxxxxxx/

>
> Best Regards
> Dillon
>
> >
> > Thanks and regards,
> > Dario
> >
> > >
> > > from stm32{f429, f469, f746, f769}_gates[]; or else
> > > run into white screen after the kernel enters the console.
> > >
> > > This patch was verified by Patrice Chotard, you can
> > > find the history from [2].
> > >
> > > Hope you can help to submit a patch to include [2], thanks.
> > >
> > > [1]
> > > https://lore.kernel.org/linux-arm-kernel/1590564453-24499-7-git-send-email-dillon.minfei@xxxxxxxxx/
> > > https://lore.kernel.org/linux-arm-kernel/1590564453-24499-6-git-send-email-dillon.minfei@xxxxxxxxx/
> > >
> > > resend this year:
> > > https://lore.kernel.org/lkml/1590378348-8115-6-git-send-email-dillon.minfei@xxxxxxxxx/
> > >
> > > [2]
> > > https://lore.kernel.org/lkml/6915fa2a-e211-476f-8317-6825e280c322@xxxxxxxxxxx/
> > >
> > > Thanks
> > > Best Regards
> > >
> > > Dillon
> > >
> > > On Mon, Jul 26, 2021 at 12:08 AM Dario Binacchi <dariobin@xxxxxxxxx> wrote:
> > > >
> > > > Enabling the framebuffer leads to a system hang. Running, as a debug
> > > > hack, the store_pan() function in drivers/video/fbdev/core/fbsysfs.c
> > > > without taking the console_lock, allows to see the crash backtrace on
> > > > the serial line.
> > > >
> > > > ~ # echo 0 0 > /sys/class/graphics/fb0/pan
> > > >
> > > > [ 9.719414] Unhandled exception: IPSR = 00000005 LR = fffffff1
> > > > [ 9.726937] CPU: 0 PID: 49 Comm: sh Not tainted 5.13.0-rc5 #9
> > > > [ 9.733008] Hardware name: STM32 (Device Tree Support)
> > > > [ 9.738296] PC is at clk_gate_is_enabled+0x0/0x28
> > > > [ 9.743426] LR is at stm32f4_pll_div_set_rate+0xf/0x38
> > > > [ 9.748857] pc : [<0011e4be>] lr : [<0011f9e3>] psr: 0100000b
> > > > [ 9.755373] sp : 00bc7be0 ip : 00000000 fp : 001f3ac4
> > > > [ 9.760812] r10: 002610d0 r9 : 01efe920 r8 : 00540560
> > > > [ 9.766269] r7 : 02e7ddb0 r6 : 0173eed8 r5 : 00000000 r4 : 004027c0
> > > > [ 9.773081] r3 : 0011e4bf r2 : 02e7ddb0 r1 : 0173eed8 r0 : 1d3267b8
> > > > [ 9.779911] xPSR: 0100000b
> > > > [ 9.782719] CPU: 0 PID: 49 Comm: sh Not tainted 5.13.0-rc5 #9
> > > > [ 9.788791] Hardware name: STM32 (Device Tree Support)
> > > > [ 9.794120] [<0000afa1>] (unwind_backtrace) from [<0000a33f>] (show_stack+0xb/0xc)
> > > > [ 9.802421] [<0000a33f>] (show_stack) from [<0000a8df>] (__invalid_entry+0x4b/0x4c)
> > > >
> > > > The `pll_num' field in the post_div_data configuration contained a wrong
> > > > value which also referenced an uninitialized hardware clock when
> > > > clk_register_pll_div() was called.
> > > >
> > > > Fixes: 517633ef630e ("clk: stm32f4: Add post divisor for I2S & SAI PLLs")
> > > > Signed-off-by: Dario Binacchi <dariobin@xxxxxxxxx>
> > > > Reviewed-by: Gabriel Fernandez <gabriel.fernandez@xxxxxx>
> > > >
> > > > ---
> > > > I added Gabriel Fernandez's 'Reviewed-by' tag as requested by himself
> > > > 15 days ago at https://lore.kernel.org/patchwork/patch/1450964/.
> > > >
> > > > Changes in v4:
> > > > - Really add Gabriel Fernandez 'Reviewed-by' tag. In version 3 I forgot
> > > > to add the tag.
> > > >
> > > > Changes in v3:
> > > > - Add Gabriel Fernandez 'Reviewed-by' tag.
> > > >
> > > > Changes in v2:
> > > > - Change 'u8 pll_num' from 'stm32f4_pll_post_div_data' structure into
> > > > 'int pll_idx'.
> > > >
> > > > drivers/clk/clk-stm32f4.c | 10 +++++-----
> > > > 1 file changed, 5 insertions(+), 5 deletions(-)
> > > >
> > > > diff --git a/drivers/clk/clk-stm32f4.c b/drivers/clk/clk-stm32f4.c
> > > > index 18117ce5ff85..5c75e3d906c2 100644
> > > > --- a/drivers/clk/clk-stm32f4.c
> > > > +++ b/drivers/clk/clk-stm32f4.c
> > > > @@ -526,7 +526,7 @@ struct stm32f4_pll {
> > > >
> > > > struct stm32f4_pll_post_div_data {
> > > > int idx;
> > > > - u8 pll_num;
> > > > + int pll_idx;
> > > > const char *name;
> > > > const char *parent;
> > > > u8 flag;
> > > > @@ -557,13 +557,13 @@ static const struct clk_div_table post_divr_table[] = {
> > > >
> > > > #define MAX_POST_DIV 3
> > > > static const struct stm32f4_pll_post_div_data post_div_data[MAX_POST_DIV] = {
> > > > - { CLK_I2SQ_PDIV, PLL_I2S, "plli2s-q-div", "plli2s-q",
> > > > + { CLK_I2SQ_PDIV, PLL_VCO_I2S, "plli2s-q-div", "plli2s-q",
> > > > CLK_SET_RATE_PARENT, STM32F4_RCC_DCKCFGR, 0, 5, 0, NULL},
> > > >
> > > > - { CLK_SAIQ_PDIV, PLL_SAI, "pllsai-q-div", "pllsai-q",
> > > > + { CLK_SAIQ_PDIV, PLL_VCO_SAI, "pllsai-q-div", "pllsai-q",
> > > > CLK_SET_RATE_PARENT, STM32F4_RCC_DCKCFGR, 8, 5, 0, NULL },
> > > >
> > > > - { NO_IDX, PLL_SAI, "pllsai-r-div", "pllsai-r", CLK_SET_RATE_PARENT,
> > > > + { NO_IDX, PLL_VCO_SAI, "pllsai-r-div", "pllsai-r", CLK_SET_RATE_PARENT,
> > > > STM32F4_RCC_DCKCFGR, 16, 2, 0, post_divr_table },
> > > > };
> > > >
> > > > @@ -1774,7 +1774,7 @@ static void __init stm32f4_rcc_init(struct device_node *np)
> > > > post_div->width,
> > > > post_div->flag_div,
> > > > post_div->div_table,
> > > > - clks[post_div->pll_num],
> > > > + clks[post_div->pll_idx],
> > > > &stm32f4_clk_lock);
> > > >
> > > > if (post_div->idx != NO_IDX)
> > > > --
> > > > 2.17.1
> > > >

Next message: Liam Beguin: "[PATCH v7 00/13] iio: afe: add temperature rescaling support"
Previous message: Pavel Skripkin: "Re: [PATCH] net: pegasus: fix uninit-value in get_interrupt_interval"
In reply to: Dillon Hua: "Re: [RESEND PATCH v4] clk: stm32f4: fix post divisor setup for I2S/SAI PLLs"
Next in thread: Stephen Boyd: "Re: [RESEND PATCH v4] clk: stm32f4: fix post divisor setup for I2S/SAI PLLs"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]