]> git.ipfire.org Git - thirdparty/kernel/linux.git/commitdiff
i2c: mux: pca9541: Use I2C adapter timeout value for arbitration timeout
authorManikanta Guntupalli <manikanta.guntupalli@amd.com>
Thu, 31 Jul 2025 12:55:35 +0000 (18:25 +0530)
committerWolfram Sang <wsa+renesas@sang-engineering.com>
Fri, 12 Sep 2025 22:19:18 +0000 (00:19 +0200)
Remove existing arbitration timeout macros and use I2C adapter timeout
value for arbitration timeout and forceful bus ownership.

I2C adapter timeout can be configurable from user space, so using it
for arbitration timeout helps in configuring the arbitration timeout
from user space depending on the use case.

Signed-off-by: Manikanta Guntupalli <manikanta.guntupalli@amd.com>
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
drivers/i2c/muxes/i2c-mux-pca9541.c

index 8663c8a7c2693638c65a486a9bfb7f7cd14d9fa5..3d8002caf7031bc52a6e83c64677b7906ccde606 100644 (file)
 #define mybus(x)       (!((x) & MYBUS) || ((x) & MYBUS) == MYBUS)
 #define busoff(x)      (!((x) & BUSON) || ((x) & BUSON) == BUSON)
 
-/* arbitration timeouts, in jiffies */
-#define ARB_TIMEOUT    (HZ / 8)        /* 125 ms until forcing bus ownership */
-#define ARB2_TIMEOUT   (HZ / 4)        /* 250 ms until acquisition failure */
-
 /* arbitration retry delays, in us */
 #define SELECT_DELAY_SHORT     50
 #define SELECT_DELAY_LONG      1000
@@ -229,6 +225,9 @@ static int pca9541_arbitrate(struct i2c_client *client)
                 */
                data->select_timeout = SELECT_DELAY_LONG;
                if (time_is_before_eq_jiffies(data->arb_timeout)) {
+                       dev_warn(&client->dev,
+                                "Arbitration timeout on I2C bus, forcing bus ownership\n");
+
                        /* Time is up, take the bus and reset it. */
                        pca9541_reg_write(client,
                                          PCA9541_CONTROL,
@@ -251,10 +250,10 @@ static int pca9541_select_chan(struct i2c_mux_core *muxc, u32 chan)
        struct pca9541 *data = i2c_mux_priv(muxc);
        struct i2c_client *client = data->client;
        int ret;
-       unsigned long timeout = jiffies + ARB2_TIMEOUT;
+       unsigned long timeout = jiffies + (2 * client->adapter->timeout);
                /* give up after this time */
 
-       data->arb_timeout = jiffies + ARB_TIMEOUT;
+       data->arb_timeout = jiffies + client->adapter->timeout;
                /* force bus ownership after this time */
 
        do {
@@ -267,6 +266,7 @@ static int pca9541_select_chan(struct i2c_mux_core *muxc, u32 chan)
                else
                        msleep(data->select_timeout / 1000);
        } while (time_is_after_eq_jiffies(timeout));
+       dev_warn(&client->dev, "Failed to acquire I2C bus, timed out\n");
 
        return -ETIMEDOUT;
 }