lkml.org 
[lkml]   [2021]   [Mar]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v1 2/2] memory: tegra20: Protect debug code with a lock
Date
Simultaneous accesses to MC_STAT h/w shouldn't be allowed since one
collection process stomps on another. There is no good reason for
polling stats in parallel in practice, nevertheless let's add a
protection lock, just for consistency.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
---
drivers/memory/tegra/tegra20.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/memory/tegra/tegra20.c b/drivers/memory/tegra/tegra20.c
index 4659c0cea30d..2db68a913b7a 100644
--- a/drivers/memory/tegra/tegra20.c
+++ b/drivers/memory/tegra/tegra20.c
@@ -5,6 +5,7 @@

#include <linux/bitfield.h>
#include <linux/delay.h>
+#include <linux/mutex.h>
#include <linux/of_device.h>
#include <linux/slab.h>
#include <linux/string.h>
@@ -55,6 +56,8 @@
/* we store collected statistics as a fixed point values */
#define MC_FX_FRAC_SCALE 100

+static DEFINE_MUTEX(tegra20_mc_stat_lock);
+
struct tegra20_mc_stat_gather {
unsigned int pri_filter;
unsigned int pri_event;
@@ -615,8 +618,12 @@ static int tegra20_mc_stats_show(struct seq_file *s, void *unused)
if (!stats)
return -ENOMEM;

+ mutex_lock(&tegra20_mc_stat_lock);
+
tegra20_mc_collect_stats(mc, stats);

+ mutex_unlock(&tegra20_mc_stat_lock);
+
seq_puts(s, "Memory client Events Timeout High priority Bandwidth ARB RW change Successive Page miss\n");
seq_puts(s, "-----------------------------------------------------------------------------------------------------\n");

--
2.30.2
\
 
 \ /
  Last update: 2021-03-23 22:07    [W:0.412 / U:0.256 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site