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From:   Fenghua Yu <fenghua.yu@intel.com>
To:     "Vinod Koul" <vkoul@kernel.org>,
        "Dave Jiang" <dave.jiang@intel.com>
Cc:     dmaengine@vger.kernel.org,
        "linux-kernel" <linux-kernel@vger.kernel.org>,
        Fenghua Yu <fenghua.yu@intel.com>,
        Michael Prinke <michael.prinke@intel.com>
Subject: [PATCH] dmaengine: idxd: Register dsa_bus_type before registering idxd sub-drivers
Date:   Sun, 24 Sep 2023 09:22:32 -0700
Message-Id: <20230924162232.1409454-1-fenghua.yu@intel.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

idxd sub-drivers belong to bus dsa_bus_type. Thus, dsa_bus_type must be
registered in dsa bus init before idxd drivers can be registered.

But the order is wrong when both idxd and idxd_bus are builtin drivers.
In this case, idxd driver is compiled and linked before idxd_bus driver.
Since the initcall order is determined by the link order, idxd sub-drivers
are registered in idxd initcall before dsa_bus_type is registered
in idxd_bus initcall. idxd initcall fails:

[   21.562803] calling  idxd_init_module+0x0/0x110 @ 1
[   21.570761] Driver 'idxd' was unable to register with bus_type 'dsa' because the bus was not initialized.
[   21.586475] initcall idxd_init_module+0x0/0x110 returned -22 after 15717 usecs
[   21.597178] calling  dsa_bus_init+0x0/0x20 @ 1

To fix the issue, compile and link idxd_bus driver before idxd driver
to ensure the right registration order.

Fixes: d9e5481fca74 ("dmaengine: dsa: move dsa_bus_type out of idxd driver to standalone")
Reported-by: Michael Prinke <michael.prinke@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
---
 drivers/dma/idxd/Makefile | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/idxd/Makefile b/drivers/dma/idxd/Makefile
index dc096839ac63..c5e679070e46 100644
--- a/drivers/dma/idxd/Makefile
+++ b/drivers/dma/idxd/Makefile
@@ -1,12 +1,12 @@
 ccflags-y += -DDEFAULT_SYMBOL_NAMESPACE=IDXD
 
+obj-$(CONFIG_INTEL_IDXD_BUS) += idxd_bus.o
+idxd_bus-y := bus.o
+
 obj-$(CONFIG_INTEL_IDXD) += idxd.o
 idxd-y := init.o irq.o device.o sysfs.o submit.o dma.o cdev.o debugfs.o
 
 idxd-$(CONFIG_INTEL_IDXD_PERFMON) += perfmon.o
 
-obj-$(CONFIG_INTEL_IDXD_BUS) += idxd_bus.o
-idxd_bus-y := bus.o
-
 obj-$(CONFIG_INTEL_IDXD_COMPAT) += idxd_compat.o
 idxd_compat-y := compat.o
-- 
2.37.1