From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes Skip the xarray reservation loop when clearing all memory attributes, as storing NULL only erases the entry and never needs to allocate, so no reservation (and no cleanup of a failed one) is required in that case. Suggested-by: Sean Christopherson Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- Documentation/ABI/testing/sysfs-class-pwm | 88 +++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-class-pwm (limited to 'Documentation/ABI/testing/sysfs-class-pwm') diff --git a/Documentation/ABI/testing/sysfs-class-pwm b/Documentation/ABI/testing/sysfs-class-pwm new file mode 100644 index 000000000..0638c94d0 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-pwm @@ -0,0 +1,88 @@ +What: /sys/class/pwm/ +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + The pwm/ class sub-directory belongs to the Generic PWM + Framework and provides a sysfs interface for using PWM + channels. + +What: /sys/class/pwm/pwmchip/ +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + A /sys/class/pwm/pwmchipN directory is created for each + probed PWM controller/chip where N is the base of the + PWM chip. + +What: /sys/class/pwm/pwmchip/npwm +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + The number of PWM channels supported by the PWM chip. + +What: /sys/class/pwm/pwmchip/export +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + Exports a PWM channel from the PWM chip for sysfs control. + Value is between 0 and /sys/class/pwm/pwmchipN/npwm - 1. + +What: /sys/class/pwm/pwmchip/unexport +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + Unexports a PWM channel. + +What: /sys/class/pwm/pwmchip/pwmX +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + A /sys/class/pwm/pwmchipN/pwmX directory is created for + each exported PWM channel where X is the exported PWM + channel number. + +What: /sys/class/pwm/pwmchip/pwmX/period +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + Sets the PWM signal period in nanoseconds. + +What: /sys/class/pwm/pwmchip/pwmX/duty_cycle +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + Sets the PWM signal duty cycle in nanoseconds. + +What: /sys/class/pwm/pwmchip/pwmX/polarity +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + Sets the output polarity of the PWM signal to "normal" or + "inversed". + +What: /sys/class/pwm/pwmchip/pwmX/enable +Date: May 2013 +KernelVersion: 3.11 +Contact: H Hartley Sweeten +Description: + Enable/disable the PWM signal. + 0 is disabled + 1 is enabled + +What: /sys/class/pwm/pwmchip/pwmX/capture +Date: June 2016 +KernelVersion: 4.8 +Contact: Lee Jones +Description: + Capture information about a PWM signal. The output format is a + pair unsigned integers (period and duty cycle), separated by a + single space. -- cgit v1.3.1