lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Mon, 11 May 2020 03:34:44 +0300 From: Serge Semin <Sergey.Semin@...kalelectronics.ru> To: Thomas Bogendoerfer <tsbogend@...ha.franken.de> CC: Serge Semin <fancer.lancer@...il.com>, Alexey Malahov <Alexey.Malahov@...kalelectronics.ru>, Paul Burton <paulburton@...nel.org>, Ralf Baechle <ralf@...ux-mips.org>, Greg Kroah-Hartman <gregkh@...uxfoundation.org>, Arnd Bergmann <arnd@...db.de>, Rob Herring <robh+dt@...nel.org>, <linux-pm@...r.kernel.org>, <devicetree@...r.kernel.org>, afzal mohammed <afzal.mohd.ma@...il.com>, <linux-mips@...r.kernel.org>, <linux-kernel@...r.kernel.org> Subject: Re: [PATCH v2 19/20] mips: cevt-r4k: Update the r4k-clockevent frequency in sync with CPU On Fri, May 08, 2020 at 05:40:46PM +0200, Thomas Bogendoerfer wrote: > On Wed, May 06, 2020 at 08:42:37PM +0300, Sergey.Semin@...kalelectronics.ru wrote: > > diff --git a/arch/mips/kernel/cevt-r4k.c b/arch/mips/kernel/cevt-r4k.c > > index 17a9cbb8b3df..f5b72fb7d5ee 100644 > > --- a/arch/mips/kernel/cevt-r4k.c > > +++ b/arch/mips/kernel/cevt-r4k.c > > @@ -8,6 +8,7 @@ > > */ > > #include <linux/clockchips.h> > > #include <linux/interrupt.h> > > +#include <linux/cpufreq.h> > > #include <linux/percpu.h> > > #include <linux/smp.h> > > #include <linux/irq.h> > > @@ -250,6 +251,49 @@ unsigned int __weak get_c0_compare_int(void) > > return MIPS_CPU_IRQ_BASE + cp0_compare_irq; > > } > > > > +#ifdef CONFIG_CPU_FREQ > > + > > +static unsigned long mips_ref_freq; > > + > > +static int cpufreq_callback(struct notifier_block *nb, > > + unsigned long val, void *data) > > please prefix function names with r4k_ to make them different from > the other ones you implemented in kernel/time.c. I know they are > static, but keeping different names makes looking at crashes easier. Agreed. I'll fix it in v3. > > > + struct cpufreq_freqs *freq = data; > > + struct clock_event_device *cd; > > + unsigned long rate; > > + int cpu; > > + > > + if (!mips_ref_freq) > > + mips_ref_freq = freq->old; > > isn't this the same as mips_hpt_frequency ? No. Here I save the initial CPU frequency so use one then to scale the mips_hpt_frequency value in accordance with the CPU clock rate change. Yes, mips_hpt_frequency value may initially match the CPU frequency on some platforms but normally the r4k timer is clocked with half of it while some systems may have a complicated algorithm of the timer ref clock rate calculation. -Sergey > > Thomas. > > -- > Crap can work. Given enough thrust pigs will fly, but it's not necessarily a > good idea. [ RFC1925, 2.3 ]
Powered by blists - more mailing lists