net: dsa: mv88e6xxx: shorten the locked section in mv88e6xxx_g1_atu_prob_irq_thread_fn()
authorHans J. Schultz <netdev@kapio-technology.com>
Sun, 8 Jan 2023 09:48:48 +0000 (10:48 +0100)
committerPaolo Abeni <pabeni@redhat.com>
Tue, 10 Jan 2023 10:58:39 +0000 (11:58 +0100)
As only the hardware access functions up til and including
mv88e6xxx_g1_atu_mac_read() called under the interrupt handler
need to take the chip lock, we release the chip lock after this call.
The follow up code that handles the violations can run without the
chip lock held.
In further patches, the violation handler function will even be
incompatible with having the chip lock held. This due to an AB/BA
ordering inversion with rtnl_lock().

Signed-off-by: Hans J. Schultz <netdev@kapio-technology.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
drivers/net/dsa/mv88e6xxx/global1_atu.c

index 61ae2d6..0a9fd25 100644 (file)
@@ -409,23 +409,25 @@ static irqreturn_t mv88e6xxx_g1_atu_prob_irq_thread_fn(int irq, void *dev_id)
 
        err = mv88e6xxx_g1_read_atu_violation(chip);
        if (err)
-               goto out;
+               goto out_unlock;
 
        err = mv88e6xxx_g1_read(chip, MV88E6XXX_G1_ATU_OP, &val);
        if (err)
-               goto out;
+               goto out_unlock;
 
        err = mv88e6xxx_g1_atu_fid_read(chip, &fid);
        if (err)
-               goto out;
+               goto out_unlock;
 
        err = mv88e6xxx_g1_atu_data_read(chip, &entry);
        if (err)
-               goto out;
+               goto out_unlock;
 
        err = mv88e6xxx_g1_atu_mac_read(chip, &entry);
        if (err)
-               goto out;
+               goto out_unlock;
+
+       mv88e6xxx_reg_unlock(chip);
 
        spid = entry.state;
 
@@ -449,13 +451,11 @@ static irqreturn_t mv88e6xxx_g1_atu_prob_irq_thread_fn(int irq, void *dev_id)
                                                   fid);
                chip->ports[spid].atu_full_violation++;
        }
-       mv88e6xxx_reg_unlock(chip);
 
        return IRQ_HANDLED;
 
-out:
+out_unlock:
        mv88e6xxx_reg_unlock(chip);
-
        dev_err(chip->dev, "ATU problem: error %d while handling interrupt\n",
                err);
        return IRQ_HANDLED;