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ANDROID: PCI/PM: Use usleep_range for d3hot_delay

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This patch implements a vendor hook that changes d3hot_delay to use
usleep_range() instead of msleep() to reduce the resume time from 20ms to 10ms.

The call sequence is as follows:
pci_pm_resume_noirq()
pci_pm_default_resume_early()
pci_power_up()
pci_raw_set_power_state() --> msleep(10)

The default d3hot_delay is 10ms. Using msleep for delays less than 20ms could
result in delays up to 20ms.
Reference: Documentation/timers/timers-howto.rst

Using usleep_range() results in the delay being closer to 10ms and this reduces
the resume time.

Bug: 194231641
Change-Id: If3e4dcfb99edad302371273933fa6784854cf892
Signed-off-by: Sajid Dalvi <sdalvi@google.com>
This commit is contained in:
Sajid Dalvi 2021-07-27 17:31:07 -05:00
parent 045204b080
commit bce9e7942a
3 changed files with 33 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/android/vendor_hooks.c
View File

@ -73,6 +73,7 @@
#include <trace/hooks/sound.h>
#include <trace/hooks/snd_compr.h>
#include <trace/hooks/ipv4.h>
#include <trace/hooks/pci.h>
/*
* Export tracepoints that act as a bare tracehook (ie: have no trace event
@ -378,3 +379,4 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_tcp_recvmsg);
EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_udp_sendmsg);
EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_udp_recvmsg);
EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_tcp_recvmsg_stat);
EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_pci_d3_sleep);

11
drivers/pci/pci.c
View File

@ -31,6 +31,9 @@
#include <linux/vmalloc.h>
#include <asm/dma.h>
#include <linux/aer.h>
#ifndef __GENKSYMS__
#include <trace/hooks/pci.h>
#endif
#include "pci.h"
DEFINE_MUTEX(pci_slot_mutex);
@ -64,12 +67,16 @@ struct pci_pme_device {
static void pci_dev_d3_sleep(struct pci_dev *dev)
{
unsigned int delay = dev->d3hot_delay;
int err = -EOPNOTSUPP;
if (delay < pci_pm_d3hot_delay)
delay = pci_pm_d3hot_delay;
if (delay)
msleep(delay);
if (delay) {
trace_android_rvh_pci_d3_sleep(dev, delay, &err);
if (err == -EOPNOTSUPP)
msleep(delay);
}
}
#ifdef CONFIG_PCI_DOMAINS

22
include/trace/hooks/pci.h Normal file
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@ -0,0 +1,22 @@
/* SPDX-License-Identifier: GPL-2.0 */
#undef TRACE_SYSTEM
#define TRACE_SYSTEM pci
#define TRACE_INCLUDE_PATH trace/hooks
#if !defined(_TRACE_HOOK_PCI_H) || defined(TRACE_HEADER_MULTI_READ)
#define _TRACE_HOOK_PCI_H
#include <linux/tracepoint.h>
#include <trace/hooks/vendor_hooks.h>
/*
* Following tracepoints are not exported in tracefs and provide a
* mechanism for vendor modules to hook and extend functionality
*/
DECLARE_RESTRICTED_HOOK(android_rvh_pci_d3_sleep,
TP_PROTO(struct pci_dev *dev, unsigned int delay, int *err),
TP_ARGS(dev, delay, err), 1);
#endif /* _TRACE_HOOK_PCI_H */
/* This part must be outside protection */
#include <trace/define_trace.h>