Messages in this thread | | | Date | Wed, 4 May 2022 08:52:14 +0200 | Subject | Re: [PATCH printk v5 1/1] printk: extend console_lock for per-console locking | From | Marek Szyprowski <> |
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Hi John,
On 04.05.2022 07:56, John Ogness wrote: > On 2022-05-03, Marek Szyprowski <m.szyprowski@samsung.com> wrote: >>> I suppose if you login via ssh and check /proc/interrupts, then type >>> some things over serial, then check /proc/interrupts again, you will >>> see there have been no interrupts for the uart. But interrupts for >>> other devices are happening. Is this correct? >> Right. The counter for ttyAML0 is not increased when lockup happens >> and I type something to the uart console. > Hmmm. This would imply that the interrupts are disabled fo the UART. > > Just to be sure that we haven't corrupted something in the driver, if > you make the following change, everything works, right? > > --------- BEGIN PATCH ------ > diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c > index c7973266b176..1eaa323e335c 100644 > --- a/kernel/printk/printk.c > +++ b/kernel/printk/printk.c > @@ -3578,7 +3578,7 @@ static int __init printk_activate_kthreads(void) > struct console *con; > > console_lock(); > - printk_kthreads_available = true; > + //printk_kthreads_available = true; > for_each_console(con) > printk_start_kthread(con); > console_unlock(); > --------- END PATCH ------ > > The above change will cause the kthreads to not print and instead always > fallback to the direct method.
With the above change console always works.
Best regards -- Marek Szyprowski, PhD Samsung R&D Institute Poland
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