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12 Commits

Author SHA1 Message Date
Linus Torvalds
d0e88704d9 Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
Pull clk fixes from Stephen Boyd:
 "Fixes for the Allwinner A523 clk driver:

   - Lower the minimum rate for the A523 audio PLL to support
     frequencies required by audio devices

   - Mark a couple clks critical on A523 so that Linux doesn't turn them
     off when they're used by other code like TF-A"

* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
  clk: sunxi-ng: sun55i-a523-ccu: Lower audio0 pll minimum rate
  clk: sunxi-ng: sun55i-a523-r-ccu: Mark bus-r-dma as critical
  clk: sunxi-ng: Mark A523 bus-r-cpucfg clock as critical
2025-11-23 12:03:28 -08:00
Linus Torvalds
1af5c1d3a9 Merge tag 'timers-urgent-2025-11-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Ingo Molnar:

 - Fix a race in timer->function clearing in timer_shutdown_sync()

 - Fix a timekeeper sysfs-setup resource leak in error paths

 - Fix the NOHZ report_idle_softirq() syslog rate-limiting
   logic to have no side effects on the return value

* tag 'timers-urgent-2025-11-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  timers: Fix NULL function pointer race in timer_shutdown_sync()
  timekeeping: Fix resource leak in tk_aux_sysfs_init() error paths
  tick/sched: Fix bogus condition in report_idle_softirq()
2025-11-23 08:23:30 -08:00
Linus Torvalds
e624f73775 Merge tag 'perf-urgent-2025-11-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "Fix perf CPU-clock counters, and address a static checker warning"

* tag 'perf-urgent-2025-11-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Fix 0 count issue of cpu-clock
  perf/x86/intel/uncore: Remove superfluous check
2025-11-23 08:20:15 -08:00
Yipeng Zou
20739af073 timers: Fix NULL function pointer race in timer_shutdown_sync()
There is a race condition between timer_shutdown_sync() and timer
expiration that can lead to hitting a WARN_ON in expire_timers().

The issue occurs when timer_shutdown_sync() clears the timer function
to NULL while the timer is still running on another CPU. The race
scenario looks like this:

CPU0					CPU1
					<SOFTIRQ>
					lock_timer_base()
					expire_timers()
					base->running_timer = timer;
					unlock_timer_base()
					[call_timer_fn enter]
					mod_timer()
					...
timer_shutdown_sync()
lock_timer_base()
// For now, will not detach the timer but only clear its function to NULL
if (base->running_timer != timer)
	ret = detach_if_pending(timer, base, true);
if (shutdown)
	timer->function = NULL;
unlock_timer_base()
					[call_timer_fn exit]
					lock_timer_base()
					base->running_timer = NULL;
					unlock_timer_base()
					...
					// Now timer is pending while its function set to NULL.
					// next timer trigger
					<SOFTIRQ>
					expire_timers()
					WARN_ON_ONCE(!fn) // hit
					...
lock_timer_base()
// Now timer will detach
if (base->running_timer != timer)
	ret = detach_if_pending(timer, base, true);
if (shutdown)
	timer->function = NULL;
unlock_timer_base()

The problem is that timer_shutdown_sync() clears the timer function
regardless of whether the timer is currently running. This can leave a
pending timer with a NULL function pointer, which triggers the
WARN_ON_ONCE(!fn) check in expire_timers().

Fix this by only clearing the timer function when actually detaching the
timer. If the timer is running, leave the function pointer intact, which is
safe because the timer will be properly detached when it finishes running.

Fixes: 0cc04e8045 ("timers: Add shutdown mechanism to the internal functions")
Signed-off-by: Yipeng Zou <zouyipeng@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20251122093942.301559-1-zouyipeng@huawei.com
2025-11-22 22:55:26 +01:00
Malaya Kumar Rout
7b5ab04f03 timekeeping: Fix resource leak in tk_aux_sysfs_init() error paths
tk_aux_sysfs_init() returns immediately on error during the auxiliary clock
initialization loop without cleaning up previously allocated kobjects and
sysfs groups.

If kobject_create_and_add() or sysfs_create_group() fails during loop
iteration, the parent kobjects (tko and auxo) and any previously created
child kobjects are leaked.

Fix this by adding proper error handling with goto labels to ensure all
allocated resources are cleaned up on failure. kobject_put() on the
parent kobjects will handle cleanup of their children.

Fixes: 7b95663a3d ("timekeeping: Provide interface to control auxiliary clocks")
Signed-off-by: Malaya Kumar Rout <mrout@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/20251120150213.246777-1-mrout@redhat.com
2025-11-20 16:40:48 +01:00
Dapeng Mi
f1f96511b1 perf: Fix 0 count issue of cpu-clock
Currently cpu-clock event always returns 0 count, e.g.,

perf stat -e cpu-clock -- sleep 1

 Performance counter stats for 'sleep 1':
                 0      cpu-clock                        #    0.000 CPUs utilized
       1.002308394 seconds time elapsed

The root cause is the commit 'bc4394e5e79c ("perf: Fix the throttle
 error of some clock events")' adds PERF_EF_UPDATE flag check before
calling cpu_clock_event_update() to update the count, however the
PERF_EF_UPDATE flag is never set when the cpu-clock event is stopped in
counting mode (pmu->dev() -> cpu_clock_event_del() ->
cpu_clock_event_stop()). This leads to the cpu-clock event count is
never updated.

To fix this issue, force to set PERF_EF_UPDATE flag for cpu-clock event
just like what task-clock does.

Fixes: bc4394e5e7 ("perf: Fix the throttle error of some clock events")
Signed-off-by: Dapeng Mi <dapeng1.mi@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://patch.msgid.link/20251112080526.3971392-1-dapeng1.mi@linux.intel.com
2025-11-20 10:42:12 +01:00
Wen Yang
807e0d187d tick/sched: Fix bogus condition in report_idle_softirq()
In commit 0345691b24 ("tick/rcu: Stop allowing RCU_SOFTIRQ in idle") the
new function report_idle_softirq() was created by breaking code out of the
existing can_stop_idle_tick() for kernels v5.18 and newer.

In doing so, the code essentially went from this form:

	if (A) {
		static int ratelimit;
		if (ratelimit < 10 && !C && A&D) {
                       pr_warn("NOHZ tick-stop error: ...");
		       ratelimit++;
		}
		return false;
	}

to a new function:

static bool report_idle_softirq(void)
{
       static int ratelimit;

       if (likely(!A))
               return false;

       if (ratelimit < 10)
               return false;
...
       pr_warn("NOHZ tick-stop error: local softirq work is pending, handler #%02x!!!\n",
               pending);
       ratelimit++;

       return true;
}

commit a7e282c777 ("tick/rcu: Fix bogus ratelimit condition") realized
ratelimit was essentially set to zero instead of ten, and hence *no*
softirq pending messages would ever be issued, but "fixed" it as:

-       if (ratelimit < 10)
+       if (ratelimit >= 10)
                return false;

However, this fix introduced another issue:

When ratelimit is greater than or equal 10, even if A is true, it will
directly return false. While ratelimit in the original code was only used
to control printing and will not affect the return value.

Restore the original logic and restrict ratelimit to control the printk and
not the return value.

Fixes: 0345691b24 ("tick/rcu: Stop allowing RCU_SOFTIRQ in idle")
Fixes: a7e282c777 ("tick/rcu: Fix bogus ratelimit condition")
Signed-off-by: Wen Yang <wen.yang@linux.dev>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://patch.msgid.link/20251119174525.29470-1-wen.yang@linux.dev
2025-11-19 19:30:45 +01:00
Stephen Boyd
3c493b524f Merge tag 'sunxi-clk-fixes-for-6.18' of https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux into clk-fixes
Pull Allwinner clk driver fixes from Chen-Yu Tsai:

Just a couple fixes for the A523 family. A couple clocks are marked as
critical, and the lower bound of the audio PLL was lowered to match
the datasheet.

* tag 'sunxi-clk-fixes-for-6.18' of https://git.kernel.org/pub/scm/linux/kernel/git/sunxi/linux:
  clk: sunxi-ng: sun55i-a523-ccu: Lower audio0 pll minimum rate
  clk: sunxi-ng: sun55i-a523-r-ccu: Mark bus-r-dma as critical
  clk: sunxi-ng: Mark A523 bus-r-cpucfg clock as critical
2025-11-19 10:59:21 -07:00
Jiri Slaby (SUSE)
a24074ca88 perf/x86/intel/uncore: Remove superfluous check
The 'pmu' pointer cannot be NULL, as it is taken as a pointer to an array.
Remove the superfluous NULL check.

Found by Coverity: CID#1497507.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Liang Kan <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20251119091538.825307-1-jirislaby@kernel.org
2025-11-19 10:26:31 +01:00
Chen-Yu Tsai
2050280a4b clk: sunxi-ng: sun55i-a523-ccu: Lower audio0 pll minimum rate
While the user manual states that the PLL's rate should be between 180
MHz and 3 GHz in the register defninition section, it also says the
actual operating frequency is 22.5792*4 MHz in the PLL features table.

22.5792*4 MHz is one of the actual clock rates that we want and is
is available in the SDM table. Lower the minimum clock rate to 90 MHz
so that both rates in the SDM table can be used.

Fixes: 7cae1e2b55 ("clk: sunxi-ng: Add support for the A523/T527 CCU PLLs")
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://patch.msgid.link/20251020171059.2786070-7-wens@kernel.org
Signed-off-by: Chen-Yu Tsai <wens@kernel.org>
2025-10-23 02:06:47 +08:00
Chen-Yu Tsai
5888533c60 clk: sunxi-ng: sun55i-a523-r-ccu: Mark bus-r-dma as critical
The "bus-r-dma" clock in the A523's PRCM clock controller is also
referred to as "DMA_CLKEN_SW" or "DMA ADB400 gating". It is unclear how
this ties into the DMA controller MBUS clock gate; however if the clock
is not enabled, the DMA controller in the MCU block will fail to access
DRAM, even failing to retrieve the DMA descriptors.

Mark this clock as critical. This sort of mirrors what is done for the
main DMA controller's MBUS clock, which has a separate toggle that is
currently left out of the main clock controller driver.

Fixes: 8cea339cfb ("clk: sunxi-ng: add support for the A523/T527 PRCM CCU")
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Link: https://patch.msgid.link/20251020171059.2786070-6-wens@kernel.org
Signed-off-by: Chen-Yu Tsai <wens@kernel.org>
2025-10-23 02:06:47 +08:00
Jernej Skrabec
1dba74abf3 clk: sunxi-ng: Mark A523 bus-r-cpucfg clock as critical
bus-r-cpucfg clock is important for peripheral which takes care of
powering CPU cores on and off. Since this operation is done by firmware
(TF-A), mark it as critical. That way Linux won't interfere with that
clock.

Fixes: 8cea339cfb ("clk: sunxi-ng: add support for the A523/T527 PRCM CCU")
Signed-off-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Tested-by: Andre Przywara <andre.przywara@arm.com>
Link: https://patch.msgid.link/20251020152704.4804-1-jernej.skrabec@gmail.com
Signed-off-by: Chen-Yu Tsai <wens@kernel.org>
2025-10-22 00:54:29 +08:00
7 changed files with 25 additions and 24 deletions

View File

@@ -1325,8 +1325,6 @@ static void uncore_pci_sub_driver_init(void)
continue;
pmu = &type->pmus[UNCORE_PCI_DEV_IDX(ids->driver_data)];
if (!pmu)
continue;
if (uncore_pci_get_dev_die_info(pci_sub_dev, &die))
continue;

View File

@@ -121,11 +121,11 @@ static SUNXI_CCU_GATE_HW(bus_r_ir_rx_clk, "bus-r-ir-rx",
&r_apb0_clk.common.hw, 0x1cc, BIT(0), 0);
static SUNXI_CCU_GATE_HW(bus_r_dma_clk, "bus-r-dma",
&r_apb0_clk.common.hw, 0x1dc, BIT(0), 0);
&r_apb0_clk.common.hw, 0x1dc, BIT(0), CLK_IS_CRITICAL);
static SUNXI_CCU_GATE_HW(bus_r_rtc_clk, "bus-r-rtc",
&r_apb0_clk.common.hw, 0x20c, BIT(0), 0);
static SUNXI_CCU_GATE_HW(bus_r_cpucfg_clk, "bus-r-cpucfg",
&r_apb0_clk.common.hw, 0x22c, BIT(0), 0);
&r_apb0_clk.common.hw, 0x22c, BIT(0), CLK_IS_CRITICAL);
static struct ccu_common *sun55i_a523_r_ccu_clks[] = {
&r_ahb_clk.common,

View File

@@ -300,7 +300,7 @@ static struct ccu_nm pll_audio0_4x_clk = {
.m = _SUNXI_CCU_DIV(16, 6),
.sdm = _SUNXI_CCU_SDM(pll_audio0_sdm_table, BIT(24),
0x178, BIT(31)),
.min_rate = 180000000U,
.min_rate = 90000000U,
.max_rate = 3000000000U,
.common = {
.reg = 0x078,

View File

@@ -11901,7 +11901,7 @@ static int cpu_clock_event_add(struct perf_event *event, int flags)
static void cpu_clock_event_del(struct perf_event *event, int flags)
{
cpu_clock_event_stop(event, flags);
cpu_clock_event_stop(event, PERF_EF_UPDATE);
}
static void cpu_clock_event_read(struct perf_event *event)

View File

@@ -1152,16 +1152,15 @@ static bool report_idle_softirq(void)
return false;
}
if (ratelimit >= 10)
return false;
/* On RT, softirq handling may be waiting on some lock */
if (local_bh_blocked())
return false;
pr_warn("NOHZ tick-stop error: local softirq work is pending, handler #%02x!!!\n",
pending);
ratelimit++;
if (ratelimit < 10) {
pr_warn("NOHZ tick-stop error: local softirq work is pending, handler #%02x!!!\n",
pending);
ratelimit++;
}
return true;
}

View File

@@ -3060,29 +3060,32 @@ static const struct attribute_group aux_clock_enable_attr_group = {
static int __init tk_aux_sysfs_init(void)
{
struct kobject *auxo, *tko = kobject_create_and_add("time", kernel_kobj);
int ret = -ENOMEM;
if (!tko)
return -ENOMEM;
return ret;
auxo = kobject_create_and_add("aux_clocks", tko);
if (!auxo) {
kobject_put(tko);
return -ENOMEM;
}
if (!auxo)
goto err_clean;
for (int i = 0; i < MAX_AUX_CLOCKS; i++) {
char id[2] = { [0] = '0' + i, };
struct kobject *clk = kobject_create_and_add(id, auxo);
if (!clk)
return -ENOMEM;
int ret = sysfs_create_group(clk, &aux_clock_enable_attr_group);
goto err_clean;
ret = sysfs_create_group(clk, &aux_clock_enable_attr_group);
if (ret)
return ret;
goto err_clean;
}
return 0;
err_clean:
kobject_put(auxo);
kobject_put(tko);
return ret;
}
late_initcall(tk_aux_sysfs_init);

View File

@@ -1458,10 +1458,11 @@ static int __try_to_del_timer_sync(struct timer_list *timer, bool shutdown)
base = lock_timer_base(timer, &flags);
if (base->running_timer != timer)
if (base->running_timer != timer) {
ret = detach_if_pending(timer, base, true);
if (shutdown)
timer->function = NULL;
if (shutdown)
timer->function = NULL;
}
raw_spin_unlock_irqrestore(&base->lock, flags);