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| author | Martin Fuzzey <martin.fuzzey@flowbird.group> | 2020-09-30 11:36:46 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-10-02 16:53:25 +0300 |
| commit | c9723750a699c3bd465493ac2be8992b72ccb105 (patch) | |
| tree | 3eb9e2e316b144a055b0633e252baae89a0f3013 /drivers | |
| parent | e84d3896fb8d1ad1d6f39866e5f416b84304bd13 (diff) | |
| download | linux-c9723750a699c3bd465493ac2be8992b72ccb105.tar.xz | |
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')
| -rw-r--r-- | drivers/w1/masters/mxc_w1.c | 14 |
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; } |