Revision 0488e2723babf8f09086fa3ce091984febe5fb28 authored by David S. Miller on 09 July 2019, 20:03:04 UTC, committed by David S. Miller on 09 July 2019, 20:03:04 UTC
Josua Mayer says:

====================
Fix hang of Armada 8040 SoC in orion-mdio

With a modular kernel as configured by Debian a hang was observed with
the Armada 8040 SoC in the Clearfog GT and Macchiatobin boards.

The 8040 SoC actually requires four clocks to be enabled for the mdio
interface to function. All 4 clocks are already specified in
armada-cp110.dtsi. It has however been missed that the orion-mdio driver
only supports enabling up to three clocks.

This patch-set allows the orion-mdio driver to handle four clocks and
adds a warning when more clocks are specified to prevent this particular
oversight in the future.

Changes since v1:
- fixed condition for priting the warning (Andrew Lunn)
- rephrased commit description for deferred probing (Andrew Lunn)
- fixed compiler warnings (kbuild test robot)
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2 parent s 7715ff1 + 433a06d
Raw File
mmu_context.c
/* Copyright (C) 2009 Red Hat, Inc.
 *
 * See ../COPYING for licensing terms.
 */

#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/sched/mm.h>
#include <linux/sched/task.h>
#include <linux/mmu_context.h>
#include <linux/export.h>

#include <asm/mmu_context.h>

/*
 * use_mm
 *	Makes the calling kernel thread take on the specified
 *	mm context.
 *	(Note: this routine is intended to be called only
 *	from a kernel thread context)
 */
void use_mm(struct mm_struct *mm)
{
	struct mm_struct *active_mm;
	struct task_struct *tsk = current;

	task_lock(tsk);
	active_mm = tsk->active_mm;
	if (active_mm != mm) {
		mmgrab(mm);
		tsk->active_mm = mm;
	}
	tsk->mm = mm;
	switch_mm(active_mm, mm, tsk);
	task_unlock(tsk);
#ifdef finish_arch_post_lock_switch
	finish_arch_post_lock_switch();
#endif

	if (active_mm != mm)
		mmdrop(active_mm);
}
EXPORT_SYMBOL_GPL(use_mm);

/*
 * unuse_mm
 *	Reverses the effect of use_mm, i.e. releases the
 *	specified mm context which was earlier taken on
 *	by the calling kernel thread
 *	(Note: this routine is intended to be called only
 *	from a kernel thread context)
 */
void unuse_mm(struct mm_struct *mm)
{
	struct task_struct *tsk = current;

	task_lock(tsk);
	sync_mm_rss(mm);
	tsk->mm = NULL;
	/* active_mm is still 'mm' */
	enter_lazy_tlb(mm, tsk);
	task_unlock(tsk);
}
EXPORT_SYMBOL_GPL(unuse_mm);
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