FAILED: patch "[PATCH] w1: mxc_w1: Fix timeout resolution problem leading to bus" failed to apply to 4.19-stable tree
Subsystems (3)
[email protected]
maintainerThe patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From c9723750a699c3bd465493ac2be8992b72ccb105 Mon Sep 17 00:00:00 2001
From: Martin Fuzzey <[email protected]>
Date: Wed, 30 Sep 2020 10:36:46 +0200
Subject: [PATCH] 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().
drivers/w1/masters/mxc_w1.c +7 -7
@@ -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 ; }
Greg KH
maintainerQuoted 10 lines · On Tue, Nov 03, 2020 at 01:11:30PM +0100, [email protected] wrote:
The patch below does not apply to the 4.19-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.thanks,
greg k-h
Quoted 7 lines
------------------ original commit in Linus's tree ------------------
Quoted 1 line
From
c9723750a699c3bd465493ac2be8992b72ccb105Mon Sep 17 00:00:00 2001From: Martin Fuzzey <[email protected]>
Date: Wed, 30 Sep 2020 10:36:46 +0200
Subject: [PATCH] w1:mxc_w1: Fix timeout resolution problem leading to bus
error
Sorry, no, this patch is fine, no problems with it.
greg k-h