Fixes for 4.19

Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/queue-4.19/i2c-pnx-fix-potential-deadlock-warning-from-del_time.patch b/queue-4.19/i2c-pnx-fix-potential-deadlock-warning-from-del_time.patch
new file mode 100644 (file)
index 0000000..0ea4e42
--- /dev/null
+++ b/queue-4.19/i2c-pnx-fix-potential-deadlock-warning-from-del_time.patch
@@ -0,0 +1,185 @@
+From a16de0f10957c63ca91624767febaca4aaebf97b Mon Sep 17 00:00:00 2001
+From: Sasha Levin <sashal@kernel.org>
+Date: Fri, 28 Jun 2024 17:25:42 +0200
+Subject: i2c: pnx: Fix potential deadlock warning from del_timer_sync() call
+ in isr
+
+From: Piotr Wojtaszczyk <piotr.wojtaszczyk@timesys.com>
+
+[ Upstream commit f63b94be6942ba82c55343e196bd09b53227618e ]
+
+When del_timer_sync() is called in an interrupt context it throws a warning
+because of potential deadlock. The timer is used only to exit from
+wait_for_completion() after a timeout so replacing the call with
+wait_for_completion_timeout() allows to remove the problematic timer and
+its related functions altogether.
+
+Fixes: 41561f28e76a ("i2c: New Philips PNX bus driver")
+Signed-off-by: Piotr Wojtaszczyk <piotr.wojtaszczyk@timesys.com>
+Signed-off-by: Andi Shyti <andi.shyti@kernel.org>
+Signed-off-by: Sasha Levin <sashal@kernel.org>
+---
+ drivers/i2c/busses/i2c-pnx.c | 48 ++++++++----------------------------
+ 1 file changed, 10 insertions(+), 38 deletions(-)
+
+diff --git a/drivers/i2c/busses/i2c-pnx.c b/drivers/i2c/busses/i2c-pnx.c
+index 6e0e546ef83fc..4d09665a72e59 100644
+--- a/drivers/i2c/busses/i2c-pnx.c
++++ b/drivers/i2c/busses/i2c-pnx.c
+@@ -15,7 +15,6 @@
+ #include <linux/ioport.h>
+ #include <linux/delay.h>
+ #include <linux/i2c.h>
+-#include <linux/timer.h>
+ #include <linux/completion.h>
+ #include <linux/platform_device.h>
+ #include <linux/io.h>
+@@ -32,7 +31,6 @@ struct i2c_pnx_mif {
+       int                     ret;            /* Return value */
+       int                     mode;           /* Interface mode */
+       struct completion       complete;       /* I/O completion */
+-      struct timer_list       timer;          /* Timeout */
+       u8 *                    buf;            /* Data buffer */
+       int                     len;            /* Length of data buffer */
+       int                     order;          /* RX Bytes to order via TX */
+@@ -117,24 +115,6 @@ static inline int wait_reset(struct i2c_pnx_algo_data *data)
+       return (timeout <= 0);
+ }
+ 
+-static inline void i2c_pnx_arm_timer(struct i2c_pnx_algo_data *alg_data)
+-{
+-      struct timer_list *timer = &alg_data->mif.timer;
+-      unsigned long expires = msecs_to_jiffies(alg_data->timeout);
+-
+-      if (expires <= 1)
+-              expires = 2;
+-
+-      del_timer_sync(timer);
+-
+-      dev_dbg(&alg_data->adapter.dev, "Timer armed at %lu plus %lu jiffies.\n",
+-              jiffies, expires);
+-
+-      timer->expires = jiffies + expires;
+-
+-      add_timer(timer);
+-}
+-
+ /**
+  * i2c_pnx_start - start a device
+  * @slave_addr:               slave address
+@@ -259,8 +239,6 @@ static int i2c_pnx_master_xmit(struct i2c_pnx_algo_data *alg_data)
+                               ~(mcntrl_afie | mcntrl_naie | mcntrl_drmie),
+                                 I2C_REG_CTL(alg_data));
+ 
+-                      del_timer_sync(&alg_data->mif.timer);
+-
+                       dev_dbg(&alg_data->adapter.dev,
+                               "%s(): Waking up xfer routine.\n",
+                               __func__);
+@@ -276,8 +254,6 @@ static int i2c_pnx_master_xmit(struct i2c_pnx_algo_data *alg_data)
+                       ~(mcntrl_afie | mcntrl_naie | mcntrl_drmie),
+                         I2C_REG_CTL(alg_data));
+ 
+-              /* Stop timer. */
+-              del_timer_sync(&alg_data->mif.timer);
+               dev_dbg(&alg_data->adapter.dev,
+                       "%s(): Waking up xfer routine after zero-xfer.\n",
+                       __func__);
+@@ -364,8 +340,6 @@ static int i2c_pnx_master_rcv(struct i2c_pnx_algo_data *alg_data)
+                                mcntrl_drmie | mcntrl_daie);
+                       iowrite32(ctl, I2C_REG_CTL(alg_data));
+ 
+-                      /* Kill timer. */
+-                      del_timer_sync(&alg_data->mif.timer);
+                       complete(&alg_data->mif.complete);
+               }
+       }
+@@ -400,8 +374,6 @@ static irqreturn_t i2c_pnx_interrupt(int irq, void *dev_id)
+                        mcntrl_drmie);
+               iowrite32(ctl, I2C_REG_CTL(alg_data));
+ 
+-              /* Stop timer, to prevent timeout. */
+-              del_timer_sync(&alg_data->mif.timer);
+               complete(&alg_data->mif.complete);
+       } else if (stat & mstatus_nai) {
+               /* Slave did not acknowledge, generate a STOP */
+@@ -419,8 +391,6 @@ static irqreturn_t i2c_pnx_interrupt(int irq, void *dev_id)
+               /* Our return value. */
+               alg_data->mif.ret = -EIO;
+ 
+-              /* Stop timer, to prevent timeout. */
+-              del_timer_sync(&alg_data->mif.timer);
+               complete(&alg_data->mif.complete);
+       } else {
+               /*
+@@ -453,9 +423,8 @@ static irqreturn_t i2c_pnx_interrupt(int irq, void *dev_id)
+       return IRQ_HANDLED;
+ }
+ 
+-static void i2c_pnx_timeout(struct timer_list *t)
++static void i2c_pnx_timeout(struct i2c_pnx_algo_data *alg_data)
+ {
+-      struct i2c_pnx_algo_data *alg_data = from_timer(alg_data, t, mif.timer);
+       u32 ctl;
+ 
+       dev_err(&alg_data->adapter.dev,
+@@ -472,7 +441,6 @@ static void i2c_pnx_timeout(struct timer_list *t)
+       iowrite32(ctl, I2C_REG_CTL(alg_data));
+       wait_reset(alg_data);
+       alg_data->mif.ret = -EIO;
+-      complete(&alg_data->mif.complete);
+ }
+ 
+ static inline void bus_reset_if_active(struct i2c_pnx_algo_data *alg_data)
+@@ -514,6 +482,7 @@ i2c_pnx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+       struct i2c_msg *pmsg;
+       int rc = 0, completed = 0, i;
+       struct i2c_pnx_algo_data *alg_data = adap->algo_data;
++      unsigned long time_left;
+       u32 stat;
+ 
+       dev_dbg(&alg_data->adapter.dev,
+@@ -548,7 +517,6 @@ i2c_pnx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+               dev_dbg(&alg_data->adapter.dev, "%s(): mode %d, %d bytes\n",
+                       __func__, alg_data->mif.mode, alg_data->mif.len);
+ 
+-              i2c_pnx_arm_timer(alg_data);
+ 
+               /* initialize the completion var */
+               init_completion(&alg_data->mif.complete);
+@@ -564,7 +532,10 @@ i2c_pnx_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+                       break;
+ 
+               /* Wait for completion */
+-              wait_for_completion(&alg_data->mif.complete);
++              time_left = wait_for_completion_timeout(&alg_data->mif.complete,
++                                                      alg_data->timeout);
++              if (time_left == 0)
++                      i2c_pnx_timeout(alg_data);
+ 
+               if (!(rc = alg_data->mif.ret))
+                       completed++;
+@@ -657,7 +628,10 @@ static int i2c_pnx_probe(struct platform_device *pdev)
+       alg_data->adapter.algo_data = alg_data;
+       alg_data->adapter.nr = pdev->id;
+ 
+-      alg_data->timeout = I2C_PNX_TIMEOUT_DEFAULT;
++      alg_data->timeout = msecs_to_jiffies(I2C_PNX_TIMEOUT_DEFAULT);
++      if (alg_data->timeout <= 1)
++              alg_data->timeout = 2;
++
+ #ifdef CONFIG_OF
+       alg_data->adapter.dev.of_node = of_node_get(pdev->dev.of_node);
+       if (pdev->dev.of_node) {
+@@ -677,8 +651,6 @@ static int i2c_pnx_probe(struct platform_device *pdev)
+       if (IS_ERR(alg_data->clk))
+               return PTR_ERR(alg_data->clk);
+ 
+-      timer_setup(&alg_data->mif.timer, i2c_pnx_timeout, 0);
+-
+       snprintf(alg_data->adapter.name, sizeof(alg_data->adapter.name),
+                "%s", pdev->name);
+ 
+-- 
+2.43.0
+

diff --git a/queue-4.19/series b/queue-4.19/series
index 9ad25d461263f34d62b7d810a361d20122dd38a4..6661d2c0939891d14e5f1bf0a7b8235f2ea35a98 100644 (file)
--- a/queue-4.19/series
+++ b/queue-4.19/series
@@ -39,3 +39,4 @@ drm-nouveau-fix-null-pointer-dereference-in-nouveau_connector_get_modes.patch
 drm-amdgpu-atomfirmware-silence-ubsan-warning.patch
 bnx2x-fix-multiple-ubsan-array-index-out-of-bounds.patch
 media-dw2102-fix-a-potential-buffer-overflow.patch
+i2c-pnx-fix-potential-deadlock-warning-from-del_time.patch