kernel/linux.git/drivers/clocksource/timer-sp804.c, branch v6.19.11

clocksource/drivers/timer-sp804: Fix an Oops when read_current_timer is called on ARM32 platforms where the SP804 is not registered as the sched_clock.

2026-02-26T23:00:46+00:00

[ Upstream commit 694921a93f3e3621e067afc545cedf6fe3b234a9 ] On SP804, the delay timer shares the same clkevt instance with sched_clock. On some platforms, when sp804_clocksource_and_sched_clock_init is called with use_sched_clock not set to 1, sched_clkevt is not properly initialized. However, sp804_register_delay_timer is invoked unconditionally, and read_current_timer() subsequently calls sp804_read on an uninitialized sched_clkevt, leading to a kernel Oops when accessing sched_clkevt->value. Declare a dedicated clkevt instance exclusively for delay timer, instead of sharing the same clkevt with sched_clock. This ensures that read_current_timer continues to work correctly regardless of whether SP804 is selected as the sched_clock. Fixes: 640594a04f11 ("clocksource/drivers/timer-sp804: Fix read_current_timer() issue when clock source is not registered") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-kbuild-all/202512250520.APOMkYRQ-lkp@intel.com/ Signed-off-by: Stephen Eta Zhou Signed-off-by: Daniel Lezcano Link: https://patch.msgid.link/20251225-fix_timersp804-v2-1-a366d7157f58@gmail.com Signed-off-by: Sasha Levin

clocksource/drivers/timer-sp804: Fix read_current_timer() issue when clock source is not registered

2025-11-26T10:24:32+00:00

Register a valid read_current_timer() function for the SP804 timer on ARM32. On ARM32 platforms, when the SP804 timer is selected as the clocksource, the driver does not register a valid read_current_timer() function. As a result, features that rely on this API—such as rdseed—consistently return incorrect values. To fix this, a delay_timer structure is registered during the SP804 driver's initialization. The read_current_timer() function is implemented using the existing sp804_read() logic, and the timer frequency is reused from the already-initialized clocksource. Signed-off-by: Stephen Eta Zhou Signed-off-by: Daniel Lezcano Link: https://patch.msgid.link/20250525-sp804-fix-read_current_timer-v4-1-87a9201fa4ec@gmail.com

clocksource/drivers/sp804: Do not use timer namespace for timer_shutdown() function

2022-11-24T14:09:10+00:00

A new "shutdown" timer state is being added to the generic timer code. One of the functions to change the timer into the state is called "timer_shutdown()". This means that there can not be other functions called "timer_shutdown()" as the timer code owns the "timer_*" name space. Rename timer_shutdown() to evt_timer_shutdown() to avoid this conflict. Signed-off-by: Steven Rostedt (Google) Signed-off-by: Thomas Gleixner Tested-by: Guenter Roeck Reviewed-by: Guenter Roeck Reviewed-by: Jacob Keller Reviewed-by: Anna-Maria Behnsen Link: https://lkml.kernel.org/r/20221106212702.182883323@goodmis.org Link: https://lore.kernel.org/all/20221105060155.592778858@goodmis.org/ Link: https://lore.kernel.org/r/20221110064147.158230501@goodmis.org Link: https://lore.kernel.org/r/20221123201624.634354813@linutronix.de

clocksource/drivers/sp804: Avoid error on multiple instances

2022-05-18T09:08:52+00:00

When a machine sports more than one SP804 timer instance, we only bring up the first one, since multiple timers of the same kind are not useful to Linux. As this is intentional behaviour, we should not return an error message, as we do today: =============== [ 0.000800] Failed to initialize '/bus@8000000/motherboard-bus@8000000/iofpga-bus@300000000/timer@120000': -22 =============== Replace the -EINVAL return with a debug message and return 0 instead. Also we do not reach the init function anymore if the DT node is disabled (as this is now handled by OF_DECLARE), so remove the explicit check for that case. This fixes a long standing bogus error when booting ARM's fastmodels. Signed-off-by: Andre Przywara Reviewed-by: Robin Murphy Link: https://lore.kernel.org/r/20220506162522.3675399-1-andre.przywara@arm.com Signed-off-by: Daniel Lezcano

clocksource/drivers/sp804: Use pr_fmt

2020-12-03T18:16:18+00:00

Add pr_fmt to prefix pr_ output. Signed-off-by: Kefeng Wang Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20201029123317.90286-5-wangkefeng.wang@huawei.com

clocksource/drivers/sp804: Correct clk_get_rate handle

2020-12-03T18:16:17+00:00

clk_get_rate won't return negative value, correct clk_get_rate handle. Signed-off-by: Kefeng Wang Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20201029123317.90286-4-wangkefeng.wang@huawei.com

clocksource/drivers/sp804: Use clk_prepare_enable and clk_disable_unprepare

2020-12-03T18:16:17+00:00

Directly use clk_prepare_enable and clk_disable_unprepare. Signed-off-by: Kefeng Wang Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20201029123317.90286-3-wangkefeng.wang@huawei.com

clocksource/drivers/sp804: Make some symbol static

2020-12-03T18:16:17+00:00

drivers/clocksource/timer-sp804.c:38:31: warning: symbol 'arm_sp804_timer' was not declared. Should it be static? drivers/clocksource/timer-sp804.c:47:31: warning: symbol 'hisi_sp804_timer' was not declared. Should it be static? drivers/clocksource/timer-sp804.c:120:12: warning: symbol 'sp804_clocksource_and_sched_clock_init' was not declared. Should it be static? drivers/clocksource/timer-sp804.c:219:12: warning: symbol 'sp804_clockevents_init' was not declared. Should it be static? And move __initdata after the variables. Signed-off-by: Kefeng Wang Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20201029123317.90286-2-wangkefeng.wang@huawei.com

clocksource/drivers/sp804: Add static for functions such as sp804_clockevents_init()

2020-12-03T18:16:09+00:00

Add static for sp804_clocksource_and_sched_clock_init() and sp804_clockevents_init(), they are only used in timer-sp804.c now. Otherwise, the following warning will be reported: drivers/clocksource/timer-sp804.c:68:12: warning: no previous prototype \ for 'sp804_clocksource_and_sched_clock_init' [-Wmissing-prototypes] drivers/clocksource/timer-sp804.c:162:12: warning: no previous prototype \ for 'sp804_clockevents_init' [-Wmissing-prototypes] Fixes: 975434f8b24a ("clocksource/drivers/sp804: Delete the leading "__" of some functions") Fixes: 65f4d7ddc7b6 ("clocksource/drivers/sp804: Remove unused sp804_timer_disable() and timer-sp804.h") Reported-by: kernel test robot Signed-off-by: Zhen Lei Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20201021012259.2067-2-thunder.leizhen@huawei.com

clocksource/drivers/sp804: Enable Hisilicon sp804 timer 64bit mode

2020-09-24T08:51:04+00:00

A 100MHZ 32-bit timer will be wrapped up less than 43s. Although the kernel maintains a software high 32-bit count in the tick IRQ. But it's not applicable to the user mode APPs. Note: The kernel still uses the lower 32 bits of the timer. Signed-off-by: Zhen Lei Signed-off-by: Daniel Lezcano Link: https://lore.kernel.org/r/20200918132237.3552-9-thunder.leizhen@huawei.com