[v2] clk: imx8mq: Mark AHB clock as critical

Commit Message

Abel Vesa July 29, 2019, 7:23 a.m. UTC

Keep the AHB clock always on since there is no driver to control it and
all the other clocks that use it as parent rely on it being always enabled.

Signed-off-by: Abel Vesa <[e-mail]>
Tested-by: Daniel Baluta <[e-mail]>
---

Changes since v1:
 * added comment in code why this clock is critical
 * added T-b by Daniel

This needs to go in ASAP to fix the boot hang.

 drivers/clk/imx/clk-imx8mq.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Fabio Estevam July 29, 2019, 12:19 p.m. UTC | #1

Hi Abel,

On Mon, Jul 29, 2019 at 4:23 AM Abel Vesa <[e-mail]> wrote:
>
> Keep the AHB clock always on since there is no driver to control it and
> all the other clocks that use it as parent rely on it being always enabled.
>
> Signed-off-by: Abel Vesa <[e-mail]>
> Tested-by: Daniel Baluta <[e-mail]>
> ---
>
> Changes since v1:
>  * added comment in code why this clock is critical
>  * added T-b by Daniel
>
> This needs to go in ASAP to fix the boot hang.

Which boot hang exactly? Are you referring to the TMU clock hang?

On the TMU clock hang, the issue was that the qoriq_thermal needs to
enable the TMU clock.

Please always provide a detailed description in the commit log.

Also, if this fixes a hang it should contain a Fixes tag.

Abel Vesa July 29, 2019, 3:07 p.m. UTC | #2

Hi Fabio,

On 19-07-29 09:19:01, Fabio Estevam wrote:
> Hi Abel,
> 
> On Mon, Jul 29, 2019 at 4:23 AM Abel Vesa <[e-mail]> wrote:
> >
> > Keep the AHB clock always on since there is no driver to control it and
> > all the other clocks that use it as parent rely on it being always enabled.
> >
> > Signed-off-by: Abel Vesa <[e-mail]>
> > Tested-by: Daniel Baluta <[e-mail]>
> > ---
> >
> > Changes since v1:
> >  * added comment in code why this clock is critical
> >  * added T-b by Daniel
> >
> > This needs to go in ASAP to fix the boot hang.
> 
> Which boot hang exactly? Are you referring to the TMU clock hang?
> 
> On the TMU clock hang, the issue was that the qoriq_thermal needs to
> enable the TMU clock.
> 
> Please always provide a detailed description in the commit log.
> 
> Also, if this fixes a hang it should contain a Fixes tag.

Please have a the explanation here:

https://lkml.org/lkml/2019/7/28/306

Fabio Estevam July 29, 2019, 3:40 p.m. UTC | #3

Hi Abel,

On Mon, Jul 29, 2019 at 12:07 PM Abel Vesa <[e-mail]> wrote:

> Please have a the explanation here:
>
> https://lkml.org/lkml/2019/7/28/306

I read that and it is still not clear for me: which hang exactly are
you referring to in your comment below the --- line?

Reading the commit log it is not clear if the patch fixes a real bug
or if it is just an improvement.

Please make this clear in the commit log.

Patch

diff --git a/drivers/clk/imx/clk-imx8mq.c b/drivers/clk/imx/clk-imx8mq.c
index 4328c22..04302f2 100644
--- a/drivers/clk/imx/clk-imx8mq.c
+++ b/drivers/clk/imx/clk-imx8mq.c
@@ -406,7 +406,8 @@  static int imx8mq_clocks_probe(struct platform_device *pdev)
 	clks[IMX8MQ_CLK_NOC_APB] = imx8m_clk_composite_critical("noc_apb", imx8mq_noc_apb_sels, base + 0x8d80);
 
 	/* AHB */
-	clks[IMX8MQ_CLK_AHB] = imx8m_clk_composite("ahb", imx8mq_ahb_sels, base + 0x9000);
+	/* AHB clock is used by the AHB bus therefore marked as critical */
+	clks[IMX8MQ_CLK_AHB] = imx8m_clk_composite_critical("ahb", imx8mq_ahb_sels, base + 0x9000);
 	clks[IMX8MQ_CLK_AUDIO_AHB] = imx8m_clk_composite("audio_ahb", imx8mq_audio_ahb_sels, base + 0x9100);
 
 	/* IPG */