Commit 715d2d96 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'timers_urgent_for_v6.1_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull timer fix from Borislav Petkov:

 - Return the proper timer register width (31 bits) for a 32-bit signed
   register in order to avoid a timer interrupt storm on ARM XGene-1
   hardware running in NO_HZ mode

* tag 'timers_urgent_for_v6.1_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/arm_arch_timer: Fix XGene-1 TVAL register math error
parents b465cf17 839a9739

drivers/clocksource/arm_arch_timer.c

+5 −2
Original line number Diff line number Diff line
@@ -806,6 +806,9 @@ static u64 __arch_timer_check_delta(void) 
		/*

		 * XGene-1 implements CVAL in terms of TVAL, meaning

		 * that the maximum timer range is 32bit. Shame on them.

		 *

		 * Note that TVAL is signed, thus has only 31 of its

		 * 32 bits to express magnitude.

		 */

		MIDR_ALL_VERSIONS(MIDR_CPU_MODEL(ARM_CPU_IMP_APM,

						 APM_CPU_PART_POTENZA)),
@@ -813,8 +816,8 @@ static u64 __arch_timer_check_delta(void) 
	};



	if (is_midr_in_range_list(read_cpuid_id(), broken_cval_midrs)) {

		pr_warn_once("Broken CNTx_CVAL_EL1, limiting width to 32bits");

		return CLOCKSOURCE_MASK(32);

		pr_warn_once("Broken CNTx_CVAL_EL1, using 31 bit TVAL instead.\n");

		return CLOCKSOURCE_MASK(31);

	}

#endif

	return CLOCKSOURCE_MASK(arch_counter_get_width());