From: Martin Fuzzey martin.fuzzey@flowbird.group
commit c9723750a699c3bd465493ac2be8992b72ccb105 upstream.
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@flo... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/w1/masters/mxc_w1.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
--- a/drivers/w1/masters/mxc_w1.c +++ b/drivers/w1/masters/mxc_w1.c @@ -15,7 +15,7 @@ #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> @@ -48,12 +48,12 @@ 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);
@@ -63,7 +63,7 @@ static u8 mxc_w1_ds2_reset_bus(void *dat /* 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; } @@ -76,12 +76,12 @@ static u8 mxc_w1_ds2_reset_bus(void *dat 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);
@@ -91,7 +91,7 @@ static u8 mxc_w1_ds2_touch_bit(void *dat /* 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; }