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authorMartin Fuzzey <martin.fuzzey@flowbird.group>2020-09-30 10:36:46 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-10-02 15:53:25 +0200
commitc9723750a699c3bd465493ac2be8992b72ccb105 (patch)
tree3eb9e2e316b144a055b0633e252baae89a0f3013 /drivers/w1
parente84d3896fb8d1ad1d6f39866e5f416b84304bd13 (diff)
downloadlinux-c9723750a699c3bd465493ac2be8992b72ccb105.tar.bz2
w1: mxc_w1: Fix timeout resolution problem leading to bus error
On my platform (i.MX53) bus access sometimes fails with w1_search: max_slave_count 64 reached, will continue next search. The reason is the use of jiffies to implement a 200us timeout in mxc_w1_ds2_touch_bit(). On some platforms the jiffies timer resolution is insufficient for this. Fix by replacing jiffies by ktime_get(). For consistency apply the same change to the other use of jiffies in mxc_w1_ds2_reset_bus(). Fixes: f80b2581a706 ("w1: mxc_w1: Optimize mxc_w1_ds2_touch_bit()") Cc: stable <stable@vger.kernel.org> Signed-off-by: Martin Fuzzey <martin.fuzzey@flowbird.group> Link: https://lore.kernel.org/r/1601455030-6607-1-git-send-email-martin.fuzzey@flowbird.group Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/w1')
-rw-r--r--drivers/w1/masters/mxc_w1.c14
1 files changed, 7 insertions, 7 deletions
diff --git a/drivers/w1/masters/mxc_w1.c b/drivers/w1/masters/mxc_w1.c
index 1ca880e01476..090cbbf9e1e2 100644
--- a/drivers/w1/masters/mxc_w1.c
+++ b/drivers/w1/masters/mxc_w1.c
@@ -7,7 +7,7 @@
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/io.h>
-#include <linux/jiffies.h>
+#include <linux/ktime.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/platform_device.h>
@@ -40,12 +40,12 @@ struct mxc_w1_device {
static u8 mxc_w1_ds2_reset_bus(void *data)
{
struct mxc_w1_device *dev = data;
- unsigned long timeout;
+ ktime_t timeout;
writeb(MXC_W1_CONTROL_RPP, dev->regs + MXC_W1_CONTROL);
/* Wait for reset sequence 511+512us, use 1500us for sure */
- timeout = jiffies + usecs_to_jiffies(1500);
+ timeout = ktime_add_us(ktime_get(), 1500);
udelay(511 + 512);
@@ -55,7 +55,7 @@ static u8 mxc_w1_ds2_reset_bus(void *data)
/* PST bit is valid after the RPP bit is self-cleared */
if (!(ctrl & MXC_W1_CONTROL_RPP))
return !(ctrl & MXC_W1_CONTROL_PST);
- } while (time_is_after_jiffies(timeout));
+ } while (ktime_before(ktime_get(), timeout));
return 1;
}
@@ -68,12 +68,12 @@ static u8 mxc_w1_ds2_reset_bus(void *data)
static u8 mxc_w1_ds2_touch_bit(void *data, u8 bit)
{
struct mxc_w1_device *dev = data;
- unsigned long timeout;
+ ktime_t timeout;
writeb(MXC_W1_CONTROL_WR(bit), dev->regs + MXC_W1_CONTROL);
/* Wait for read/write bit (60us, Max 120us), use 200us for sure */
- timeout = jiffies + usecs_to_jiffies(200);
+ timeout = ktime_add_us(ktime_get(), 200);
udelay(60);
@@ -83,7 +83,7 @@ static u8 mxc_w1_ds2_touch_bit(void *data, u8 bit)
/* RDST bit is valid after the WR1/RD bit is self-cleared */
if (!(ctrl & MXC_W1_CONTROL_WR(bit)))
return !!(ctrl & MXC_W1_CONTROL_RDST);
- } while (time_is_after_jiffies(timeout));
+ } while (ktime_before(ktime_get(), timeout));
return 0;
}