[git pull][PATCH 0/2] Fix regression caused by addition of 'of_match'

[git pull][PATCH 0/2] Fix regression caused by addition of 'of_match'

[Grant Likely]

Hi Linus,

Here is Milton's patch to fix up the race condition on devicetree
driver matching observed on SPARC, plus a follow up patch to remove
the whole of_match thing entirely, which I've tested on my platforms,
but has not yet been verified by anyone else.

I'll leave it up to you whether to take both commits, or just the
first one.  The second does eventually need to be committed to 2.6.39,
whether by you or in -stable, but it is a much bigger commit and it
hasn't had any testing beyond what I've done here (a handful of
powerpc, sparc, x86, and mips defconfigs, plus boot testing on
powerpc and making sure each driver was compiled in at least one
config).

I've pushed it all out to my git server as show below...

---
The following changes since commit 2e9521fd656f05a716b5294a7dbebd37ced05e43:

Merge branch 'v4l_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-2.6 (2011-05-18 03:16:38 -0700)

are available in the git repository at:

  git://git.secretlab.ca/git/linux-2.6 devicetree/merge

Grant Likely (1):
      drivercore: revert addition of of_match to struct device

Milton Miller (1):
      of: fix race when matching drivers


 arch/powerpc/platforms/83xx/suspend.c      |    7 +++++--
 arch/powerpc/sysdev/fsl_msi.c              |    7 +++++--
 arch/sparc/kernel/pci_sabre.c              |    5 ++++-
 arch/sparc/kernel/pci_schizo.c             |    8 ++++++--
 drivers/atm/fore200e.c                     |    7 +++++--
 drivers/char/hw_random/n2-drv.c            |    7 +++++--
 drivers/char/ipmi/ipmi_si_intf.c           |    7 +++++--
 drivers/char/xilinx_hwicap/xilinx_hwicap.c |   14 +++++++++-----
 drivers/edac/ppc4xx_edac.c                 |    2 +-
 drivers/i2c/busses/i2c-mpc.c               |    9 ++++++---
 drivers/mmc/host/sdhci-of-core.c           |    7 +++++--
 drivers/mtd/maps/physmap_of.c              |    7 +++++--
 drivers/net/can/mscan/mpc5xxx_can.c        |    7 +++++--
 drivers/net/fs_enet/fs_enet-main.c         |    9 ++++++---
 drivers/net/fs_enet/mii-fec.c              |    7 +++++--
 drivers/net/sunhme.c                       |    7 +++++--
 drivers/scsi/qlogicpti.c                   |    7 +++++--
 drivers/tty/serial/of_serial.c             |    7 +++++--
 drivers/usb/gadget/fsl_qe_udc.c            |    7 +++++--
 drivers/watchdog/mpc8xxx_wdt.c             |    7 +++++--
 include/linux/device.h                     |    1 -
 include/linux/of_device.h                  |    8 ++++++--
 22 files changed, 108 insertions(+), 46 deletions(-)

-- 
Signature

[PATCH 1/2] of: fix race when matching drivers

[Grant Likely]

From: Milton Miller <miltonm-ogEGBHC/i9Y@public.gmane.org>

If two drivers are probing devices at the same time, both will write
their match table result to the dev->of_match cache at the same time.

Only write the result if the device matches.

In a thread titled "SBus devices sometimes detected, sometimes not",
Meelis reported his SBus hme was not detected about 50% of the time.
>From the debug suggested by Grant it was obvious another driver matched
some devices between the call to match the hme and the hme discovery
failling.

Reported-by: Meelis Roos <mroos-Y27EyoLml9s@public.gmane.org>
Signed-off-by: Milton Miller <miltonm-ogEGBHC/i9Y@public.gmane.org>
[grant.likely: modified to only call of_match_device() once]
Signed-off-by: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>
---
 include/linux/of_device.h |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/include/linux/of_device.h b/include/linux/of_device.h
index 8bfe6c1..b33d688 100644
--- a/include/linux/of_device.h
+++ b/include/linux/of_device.h
@@ -21,8 +21,12 @@ extern void of_device_make_bus_id(struct device *dev);
 static inline int of_driver_match_device(struct device *dev,
 					 const struct device_driver *drv)
 {
-	dev->of_match = of_match_device(drv->of_match_table, dev);
-	return dev->of_match != NULL;
+	const struct of_device_id *match;
+
+	match = of_match_device(drv->of_match_table, dev);
+	if (match)
+		dev->of_match = match;
+	return match != NULL;
 }
 
 extern struct platform_device *of_dev_get(struct platform_device *dev);

[PATCH 2/2] drivercore: revert addition of of_match to struct device

[Grant Likely]

Commit b826291c, "drivercore/dt: add a match table pointer to struct
device" added an of_match pointer to struct device to cache the
of_match_table entry discovered at driver match time.  This was unsafe
because matching is not an atomic operation with probing a driver.  If
two or more drivers are attempted to be matched to a driver at the
same time, then the cached matching entry pointer could get
overwritten.

This patch reverts the of_match cache pointer and reworks all users to
call of_match_device() directly instead.

Signed-off-by: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>
---
 arch/powerpc/platforms/83xx/suspend.c      |    7 +++++--
 arch/powerpc/sysdev/fsl_msi.c              |    7 +++++--
 arch/sparc/kernel/pci_sabre.c              |    5 ++++-
 arch/sparc/kernel/pci_schizo.c             |    8 ++++++--
 drivers/atm/fore200e.c                     |    7 +++++--
 drivers/char/hw_random/n2-drv.c            |    7 +++++--
 drivers/char/ipmi/ipmi_si_intf.c           |    7 +++++--
 drivers/char/xilinx_hwicap/xilinx_hwicap.c |   14 +++++++++-----
 drivers/edac/ppc4xx_edac.c                 |    2 +-
 drivers/i2c/busses/i2c-mpc.c               |    9 ++++++---
 drivers/mmc/host/sdhci-of-core.c           |    7 +++++--
 drivers/mtd/maps/physmap_of.c              |    7 +++++--
 drivers/net/can/mscan/mpc5xxx_can.c        |    7 +++++--
 drivers/net/fs_enet/fs_enet-main.c         |    9 ++++++---
 drivers/net/fs_enet/mii-fec.c              |    7 +++++--
 drivers/net/sunhme.c                       |    7 +++++--
 drivers/scsi/qlogicpti.c                   |    7 +++++--
 drivers/tty/serial/of_serial.c             |    7 +++++--
 drivers/usb/gadget/fsl_qe_udc.c            |    7 +++++--
 drivers/watchdog/mpc8xxx_wdt.c             |    7 +++++--
 include/linux/device.h                     |    1 -
 include/linux/of_device.h                  |   12 ++++++------
 22 files changed, 108 insertions(+), 50 deletions(-)

diff --git a/arch/powerpc/platforms/83xx/suspend.c b/arch/powerpc/platforms/83xx/suspend.c
index 1882729..104faa8 100644
--- a/arch/powerpc/platforms/83xx/suspend.c
+++ b/arch/powerpc/platforms/83xx/suspend.c
@@ -318,17 +318,20 @@ static const struct platform_suspend_ops mpc83xx_suspend_ops = {
 	.end = mpc83xx_suspend_end,
 };
 
+static struct of_device_id pmc_match[];
 static int pmc_probe(struct platform_device *ofdev)
 {
+	const struct of_device_id *match;
 	struct device_node *np = ofdev->dev.of_node;
 	struct resource res;
 	struct pmc_type *type;
 	int ret = 0;
 
-	if (!ofdev->dev.of_match)
+	match = of_match_device(pmc_match, &ofdev->dev);
+	if (!match)
 		return -EINVAL;
 
-	type = ofdev->dev.of_match->data;
+	type = match->data;
 
 	if (!of_device_is_available(np))
 		return -ENODEV;
diff --git a/arch/powerpc/sysdev/fsl_msi.c b/arch/powerpc/sysdev/fsl_msi.c
index d5679dc..01cd2f0 100644
--- a/arch/powerpc/sysdev/fsl_msi.c
+++ b/arch/powerpc/sysdev/fsl_msi.c
@@ -304,8 +304,10 @@ static int __devinit fsl_msi_setup_hwirq(struct fsl_msi *msi,
 	return 0;
 }
 
+static const struct of_device_id fsl_of_msi_ids[];
 static int __devinit fsl_of_msi_probe(struct platform_device *dev)
 {
+	const struct of_device_id *match;
 	struct fsl_msi *msi;
 	struct resource res;
 	int err, i, j, irq_index, count;
@@ -316,9 +318,10 @@ static int __devinit fsl_of_msi_probe(struct platform_device *dev)
 	u32 offset;
 	static const u32 all_avail[] = { 0, NR_MSI_IRQS };
 
-	if (!dev->dev.of_match)
+	match = of_match_device(fsl_of_msi_ids, &dev->dev);
+	if (!match)
 		return -EINVAL;
-	features = dev->dev.of_match->data;
+	features = match->data;
 
 	printk(KERN_DEBUG "Setting up Freescale MSI support\n");
 
diff --git a/arch/sparc/kernel/pci_sabre.c b/arch/sparc/kernel/pci_sabre.c
index 948068a..d1840db 100644
--- a/arch/sparc/kernel/pci_sabre.c
+++ b/arch/sparc/kernel/pci_sabre.c
@@ -452,8 +452,10 @@ static void __devinit sabre_pbm_init(struct pci_pbm_info *pbm,
 	sabre_scan_bus(pbm, &op->dev);
 }
 
+static const struct of_device_id sabre_match[];
 static int __devinit sabre_probe(struct platform_device *op)
 {
+	const struct of_device_id *match;
 	const struct linux_prom64_registers *pr_regs;
 	struct device_node *dp = op->dev.of_node;
 	struct pci_pbm_info *pbm;
@@ -463,7 +465,8 @@ static int __devinit sabre_probe(struct platform_device *op)
 	const u32 *vdma;
 	u64 clear_irq;
 
-	hummingbird_p = op->dev.of_match && (op->dev.of_match->data != NULL);
+	match = of_match_device(sabre_match, &op->dev);
+	hummingbird_p = match && (match->data != NULL);
 	if (!hummingbird_p) {
 		struct device_node *cpu_dp;
 
diff --git a/arch/sparc/kernel/pci_schizo.c b/arch/sparc/kernel/pci_schizo.c
index fecfcb2..283fbc3 100644
--- a/arch/sparc/kernel/pci_schizo.c
+++ b/arch/sparc/kernel/pci_schizo.c
@@ -1458,11 +1458,15 @@ out_err:
 	return err;
 }
 
+static const struct of_device_id schizo_match[];
 static int __devinit schizo_probe(struct platform_device *op)
 {
-	if (!op->dev.of_match)
+	const struct of_device_id *match;
+
+	match = of_match_device(schizo_match, &op->dev);
+	if (!match)
 		return -EINVAL;
-	return __schizo_init(op, (unsigned long) op->dev.of_match->data);
+	return __schizo_init(op, (unsigned long)match->data);
 }
 
 /* The ordering of this table is very important.  Some Tomatillo
diff --git a/drivers/atm/fore200e.c b/drivers/atm/fore200e.c
index bdd2719..bc9e702 100644
--- a/drivers/atm/fore200e.c
+++ b/drivers/atm/fore200e.c
@@ -2643,16 +2643,19 @@ fore200e_init(struct fore200e* fore200e, struct device *parent)
 }
 
 #ifdef CONFIG_SBUS
+static const struct of_device_id fore200e_sba_match[];
 static int __devinit fore200e_sba_probe(struct platform_device *op)
 {
+	const struct of_device_id *match;
 	const struct fore200e_bus *bus;
 	struct fore200e *fore200e;
 	static int index = 0;
 	int err;
 
-	if (!op->dev.of_match)
+	match = of_match_device(fore200e_sba_match, &op->dev);
+	if (!match)
 		return -EINVAL;
-	bus = op->dev.of_match->data;
+	bus = match->data;
 
 	fore200e = kzalloc(sizeof(struct fore200e), GFP_KERNEL);
 	if (!fore200e)
diff --git a/drivers/char/hw_random/n2-drv.c b/drivers/char/hw_random/n2-drv.c
index 43ac619..ac6739e 100644
--- a/drivers/char/hw_random/n2-drv.c
+++ b/drivers/char/hw_random/n2-drv.c
@@ -619,15 +619,18 @@ static void __devinit n2rng_driver_version(void)
 		pr_info("%s", version);
 }
 
+static const struct of_device_id n2rng_match[];
 static int __devinit n2rng_probe(struct platform_device *op)
 {
+	const struct of_device_id *match;
 	int victoria_falls;
 	int err = -ENOMEM;
 	struct n2rng *np;
 
-	if (!op->dev.of_match)
+	match = of_match_device(n2rng_match, &op->dev);
+	if (!match)
 		return -EINVAL;
-	victoria_falls = (op->dev.of_match->data != NULL);
+	victoria_falls = (match->data != NULL);
 
 	n2rng_driver_version();
 	np = kzalloc(sizeof(*np), GFP_KERNEL);
diff --git a/drivers/char/ipmi/ipmi_si_intf.c b/drivers/char/ipmi/ipmi_si_intf.c
index cc6c9b2..64c6b85 100644
--- a/drivers/char/ipmi/ipmi_si_intf.c
+++ b/drivers/char/ipmi/ipmi_si_intf.c
@@ -2554,9 +2554,11 @@ static struct pci_driver ipmi_pci_driver = {
 };
 #endif /* CONFIG_PCI */
 
+static struct of_device_id ipmi_match[];
 static int __devinit ipmi_probe(struct platform_device *dev)
 {
 #ifdef CONFIG_OF
+	const struct of_device_id *match;
 	struct smi_info *info;
 	struct resource resource;
 	const __be32 *regsize, *regspacing, *regshift;
@@ -2566,7 +2568,8 @@ static int __devinit ipmi_probe(struct platform_device *dev)
 
 	dev_info(&dev->dev, "probing via device tree\n");
 
-	if (!dev->dev.of_match)
+	match = of_match_device(ipmi_match, &dev->dev);
+	if (!match)
 		return -EINVAL;
 
 	ret = of_address_to_resource(np, 0, &resource);
@@ -2601,7 +2604,7 @@ static int __devinit ipmi_probe(struct platform_device *dev)
 		return -ENOMEM;
 	}
 
-	info->si_type		= (enum si_type) dev->dev.of_match->data;
+	info->si_type		= (enum si_type) match->data;
 	info->addr_source	= SI_DEVICETREE;
 	info->irq_setup		= std_irq_setup;
 
diff --git a/drivers/char/xilinx_hwicap/xilinx_hwicap.c b/drivers/char/xilinx_hwicap/xilinx_hwicap.c
index d6412c1..39ccdea 100644
--- a/drivers/char/xilinx_hwicap/xilinx_hwicap.c
+++ b/drivers/char/xilinx_hwicap/xilinx_hwicap.c
@@ -715,13 +715,13 @@ static int __devexit hwicap_remove(struct device *dev)
 }
 
 #ifdef CONFIG_OF
-static int __devinit hwicap_of_probe(struct platform_device *op)
+static int __devinit hwicap_of_probe(struct platform_device *op,
+				     const struct hwicap_driver_config *config)
 {
 	struct resource res;
 	const unsigned int *id;
 	const char *family;
 	int rc;
-	const struct hwicap_driver_config *config = op->dev.of_match->data;
 	const struct config_registers *regs;
 
 
@@ -751,20 +751,24 @@ static int __devinit hwicap_of_probe(struct platform_device *op)
 			regs);
 }
 #else
-static inline int hwicap_of_probe(struct platform_device *op)
+static inline int hwicap_of_probe(struct platform_device *op,
+				  const struct hwicap_driver_config *config)
 {
 	return -EINVAL;
 }
 #endif /* CONFIG_OF */
 
+static const struct of_device_id __devinitconst hwicap_of_match[];
 static int __devinit hwicap_drv_probe(struct platform_device *pdev)
 {
+	const struct of_device_id *match;
 	struct resource *res;
 	const struct config_registers *regs;
 	const char *family;
 
-	if (pdev->dev.of_match)
-		return hwicap_of_probe(pdev);
+	match = of_match_device(hwicap_of_match, &pdev->dev);
+	if (match)
+		return hwicap_of_probe(pdev, match->data);
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (!res)
diff --git a/drivers/edac/ppc4xx_edac.c b/drivers/edac/ppc4xx_edac.c
index c1f0045..af8e7b1 100644
--- a/drivers/edac/ppc4xx_edac.c
+++ b/drivers/edac/ppc4xx_edac.c
@@ -1019,7 +1019,7 @@ ppc4xx_edac_mc_init(struct mem_ctl_info *mci,
 	struct ppc4xx_edac_pdata *pdata = NULL;
 	const struct device_node *np = op->dev.of_node;
 
-	if (op->dev.of_match == NULL)
+	if (of_match_device(ppc4xx_edac_match, &op->dev) == NULL)
 		return -EINVAL;
 
 	/* Initial driver pointers and private data */
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
index 75b984c..107397a 100644
--- a/drivers/i2c/busses/i2c-mpc.c
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -560,15 +560,18 @@ static struct i2c_adapter mpc_ops = {
 	.timeout = HZ,
 };
 
+static const struct of_device_id mpc_i2c_of_match[];
 static int __devinit fsl_i2c_probe(struct platform_device *op)
 {
+	const struct of_device_id *match;
 	struct mpc_i2c *i2c;
 	const u32 *prop;
 	u32 clock = MPC_I2C_CLOCK_LEGACY;
 	int result = 0;
 	int plen;
 
-	if (!op->dev.of_match)
+	match = of_match_device(mpc_i2c_of_match, &op->dev);
+	if (!match)
 		return -EINVAL;
 
 	i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
@@ -605,8 +608,8 @@ static int __devinit fsl_i2c_probe(struct platform_device *op)
 			clock = *prop;
 	}
 
-	if (op->dev.of_match->data) {
-		struct mpc_i2c_data *data = op->dev.of_match->data;
+	if (match->data) {
+		struct mpc_i2c_data *data = match->data;
 		data->setup(op->dev.of_node, i2c, clock, data->prescaler);
 	} else {
 		/* Backwards compatibility */
diff --git a/drivers/mmc/host/sdhci-of-core.c b/drivers/mmc/host/sdhci-of-core.c
index f9b611f..60e4186 100644
--- a/drivers/mmc/host/sdhci-of-core.c
+++ b/drivers/mmc/host/sdhci-of-core.c
@@ -124,8 +124,10 @@ static bool __devinit sdhci_of_wp_inverted(struct device_node *np)
 #endif
 }
 
+static const struct of_device_id sdhci_of_match[];
 static int __devinit sdhci_of_probe(struct platform_device *ofdev)
 {
+	const struct of_device_id *match;
 	struct device_node *np = ofdev->dev.of_node;
 	struct sdhci_of_data *sdhci_of_data;
 	struct sdhci_host *host;
@@ -134,9 +136,10 @@ static int __devinit sdhci_of_probe(struct platform_device *ofdev)
 	int size;
 	int ret;
 
-	if (!ofdev->dev.of_match)
+	match = of_match_device(sdhci_of_match, &ofdev->dev);
+	if (!match)
 		return -EINVAL;
-	sdhci_of_data = ofdev->dev.of_match->data;
+	sdhci_of_data = match->data;
 
 	if (!of_device_is_available(np))
 		return -ENODEV;
diff --git a/drivers/mtd/maps/physmap_of.c b/drivers/mtd/maps/physmap_of.c
index bd483f0..c1d3346 100644
--- a/drivers/mtd/maps/physmap_of.c
+++ b/drivers/mtd/maps/physmap_of.c
@@ -214,11 +214,13 @@ static void __devinit of_free_probes(const char **probes)
 }
 #endif
 
+static struct of_device_id of_flash_match[];
 static int __devinit of_flash_probe(struct platform_device *dev)
 {
 #ifdef CONFIG_MTD_PARTITIONS
 	const char **part_probe_types;
 #endif
+	const struct of_device_id *match;
 	struct device_node *dp = dev->dev.of_node;
 	struct resource res;
 	struct of_flash *info;
@@ -232,9 +234,10 @@ static int __devinit of_flash_probe(struct platform_device *dev)
 	struct mtd_info **mtd_list = NULL;
 	resource_size_t res_size;
 
-	if (!dev->dev.of_match)
+	match = of_match_device(of_flash_match, &dev->dev);
+	if (!match)
 		return -EINVAL;
-	probe_type = dev->dev.of_match->data;
+	probe_type = match->data;
 
 	reg_tuple_size = (of_n_addr_cells(dp) + of_n_size_cells(dp)) * sizeof(u32);
 
diff --git a/drivers/net/can/mscan/mpc5xxx_can.c b/drivers/net/can/mscan/mpc5xxx_can.c
index bd1d811..5fedc33 100644
--- a/drivers/net/can/mscan/mpc5xxx_can.c
+++ b/drivers/net/can/mscan/mpc5xxx_can.c
@@ -247,8 +247,10 @@ static u32 __devinit mpc512x_can_get_clock(struct platform_device *ofdev,
 }
 #endif /* CONFIG_PPC_MPC512x */
 
+static struct of_device_id mpc5xxx_can_table[];
 static int __devinit mpc5xxx_can_probe(struct platform_device *ofdev)
 {
+	const struct of_device_id *match;
 	struct mpc5xxx_can_data *data;
 	struct device_node *np = ofdev->dev.of_node;
 	struct net_device *dev;
@@ -258,9 +260,10 @@ static int __devinit mpc5xxx_can_probe(struct platform_device *ofdev)
 	int irq, mscan_clksrc = 0;
 	int err = -ENOMEM;
 
-	if (!ofdev->dev.of_match)
+	match = of_match_device(mpc5xxx_can_table, &ofdev->dev);
+	if (!match)
 		return -EINVAL;
-	data = (struct mpc5xxx_can_data *)ofdev->dev.of_match->data;
+	data = match->data;
 
 	base = of_iomap(np, 0);
 	if (!base) {
diff --git a/drivers/net/fs_enet/fs_enet-main.c b/drivers/net/fs_enet/fs_enet-main.c
index 24cb953..5131e61 100644
--- a/drivers/net/fs_enet/fs_enet-main.c
+++ b/drivers/net/fs_enet/fs_enet-main.c
@@ -998,8 +998,10 @@ static const struct net_device_ops fs_enet_netdev_ops = {
 #endif
 };
 
+static struct of_device_id fs_enet_match[];
 static int __devinit fs_enet_probe(struct platform_device *ofdev)
 {
+	const struct of_device_id *match;
 	struct net_device *ndev;
 	struct fs_enet_private *fep;
 	struct fs_platform_info *fpi;
@@ -1007,14 +1009,15 @@ static int __devinit fs_enet_probe(struct platform_device *ofdev)
 	const u8 *mac_addr;
 	int privsize, len, ret = -ENODEV;
 
-	if (!ofdev->dev.of_match)
+	match = of_match_device(fs_enet_match, &ofdev->dev);
+	if (!match)
 		return -EINVAL;
 
 	fpi = kzalloc(sizeof(*fpi), GFP_KERNEL);
 	if (!fpi)
 		return -ENOMEM;
 
-	if (!IS_FEC(ofdev->dev.of_match)) {
+	if (!IS_FEC(match)) {
 		data = of_get_property(ofdev->dev.of_node, "fsl,cpm-command", &len);
 		if (!data || len != 4)
 			goto out_free_fpi;
@@ -1049,7 +1052,7 @@ static int __devinit fs_enet_probe(struct platform_device *ofdev)
 	fep->dev = &ofdev->dev;
 	fep->ndev = ndev;
 	fep->fpi = fpi;
-	fep->ops = ofdev->dev.of_match->data;
+	fep->ops = match->data;
 
 	ret = fep->ops->setup_data(ndev);
 	if (ret)
diff --git a/drivers/net/fs_enet/mii-fec.c b/drivers/net/fs_enet/mii-fec.c
index 7e840d3..6a2e150 100644
--- a/drivers/net/fs_enet/mii-fec.c
+++ b/drivers/net/fs_enet/mii-fec.c
@@ -101,17 +101,20 @@ static int fs_enet_fec_mii_reset(struct mii_bus *bus)
 	return 0;
 }
 
+static struct of_device_id fs_enet_mdio_fec_match[];
 static int __devinit fs_enet_mdio_probe(struct platform_device *ofdev)
 {
+	const struct of_device_id *match;
 	struct resource res;
 	struct mii_bus *new_bus;
 	struct fec_info *fec;
 	int (*get_bus_freq)(struct device_node *);
 	int ret = -ENOMEM, clock, speed;
 
-	if (!ofdev->dev.of_match)
+	match = of_match_device(fs_enet_mdio_fec_match, &ofdev->dev);
+	if (!match)
 		return -EINVAL;
-	get_bus_freq = ofdev->dev.of_match->data;
+	get_bus_freq = match->data;
 
 	new_bus = mdiobus_alloc();
 	if (!new_bus)
diff --git a/drivers/net/sunhme.c b/drivers/net/sunhme.c
index eb4f59f..bff2f79 100644
--- a/drivers/net/sunhme.c
+++ b/drivers/net/sunhme.c
@@ -3237,15 +3237,18 @@ static void happy_meal_pci_exit(void)
 #endif
 
 #ifdef CONFIG_SBUS
+static const struct of_device_id hme_sbus_match[];
 static int __devinit hme_sbus_probe(struct platform_device *op)
 {
+	const struct of_device_id *match;
 	struct device_node *dp = op->dev.of_node;
 	const char *model = of_get_property(dp, "model", NULL);
 	int is_qfe;
 
-	if (!op->dev.of_match)
+	match = of_match_device(hme_sbus_match, &op->dev);
+	if (!match)
 		return -EINVAL;
-	is_qfe = (op->dev.of_match->data != NULL);
+	is_qfe = (match->data != NULL);
 
 	if (!is_qfe && model && !strcmp(model, "SUNW,sbus-qfe"))
 		is_qfe = 1;
diff --git a/drivers/scsi/qlogicpti.c b/drivers/scsi/qlogicpti.c
index e2d45c9..9689d41c 100644
--- a/drivers/scsi/qlogicpti.c
+++ b/drivers/scsi/qlogicpti.c
@@ -1292,8 +1292,10 @@ static struct scsi_host_template qpti_template = {
 	.use_clustering		= ENABLE_CLUSTERING,
 };
 
+static const struct of_device_id qpti_match[];
 static int __devinit qpti_sbus_probe(struct platform_device *op)
 {
+	const struct of_device_id *match;
 	struct scsi_host_template *tpnt;
 	struct device_node *dp = op->dev.of_node;
 	struct Scsi_Host *host;
@@ -1301,9 +1303,10 @@ static int __devinit qpti_sbus_probe(struct platform_device *op)
 	static int nqptis;
 	const char *fcode;
 
-	if (!op->dev.of_match)
+	match = of_match_device(qpti_match, &op->dev);
+	if (!match)
 		return -EINVAL;
-	tpnt = op->dev.of_match->data;
+	tpnt = match->data;
 
 	/* Sometimes Antares cards come up not completely
 	 * setup, and we get a report of a zero IRQ.
diff --git a/drivers/tty/serial/of_serial.c b/drivers/tty/serial/of_serial.c
index 0e8eec5..c911b24 100644
--- a/drivers/tty/serial/of_serial.c
+++ b/drivers/tty/serial/of_serial.c
@@ -80,14 +80,17 @@ static int __devinit of_platform_serial_setup(struct platform_device *ofdev,
 /*
  * Try to register a serial port
  */
+static struct of_device_id of_platform_serial_table[];
 static int __devinit of_platform_serial_probe(struct platform_device *ofdev)
 {
+	const struct of_device_id *match;
 	struct of_serial_info *info;
 	struct uart_port port;
 	int port_type;
 	int ret;
 
-	if (!ofdev->dev.of_match)
+	match = of_match_device(of_platform_serial_table, &ofdev->dev);
+	if (!match)
 		return -EINVAL;
 
 	if (of_find_property(ofdev->dev.of_node, "used-by-rtas", NULL))
@@ -97,7 +100,7 @@ static int __devinit of_platform_serial_probe(struct platform_device *ofdev)
 	if (info == NULL)
 		return -ENOMEM;
 
-	port_type = (unsigned long)ofdev->dev.of_match->data;
+	port_type = (unsigned long)match->data;
 	ret = of_platform_serial_setup(ofdev, port_type, &port);
 	if (ret)
 		goto out;
diff --git a/drivers/usb/gadget/fsl_qe_udc.c b/drivers/usb/gadget/fsl_qe_udc.c
index 36613b3..3a68e09 100644
--- a/drivers/usb/gadget/fsl_qe_udc.c
+++ b/drivers/usb/gadget/fsl_qe_udc.c
@@ -2539,15 +2539,18 @@ static void qe_udc_release(struct device *dev)
 }
 
 /* Driver probe functions */
+static const struct of_device_id qe_udc_match[];
 static int __devinit qe_udc_probe(struct platform_device *ofdev)
 {
+	const struct of_device_id *match;
 	struct device_node *np = ofdev->dev.of_node;
 	struct qe_ep *ep;
 	unsigned int ret = 0;
 	unsigned int i;
 	const void *prop;
 
-	if (!ofdev->dev.of_match)
+	match = of_match_device(qe_udc_match, &ofdev->dev);
+	if (!match)
 		return -EINVAL;
 
 	prop = of_get_property(np, "mode", NULL);
@@ -2561,7 +2564,7 @@ static int __devinit qe_udc_probe(struct platform_device *ofdev)
 		return -ENOMEM;
 	}
 
-	udc_controller->soc_type = (unsigned long)ofdev->dev.of_match->data;
+	udc_controller->soc_type = (unsigned long)match->data;
 	udc_controller->usb_regs = of_iomap(np, 0);
 	if (!udc_controller->usb_regs) {
 		ret = -ENOMEM;
diff --git a/drivers/watchdog/mpc8xxx_wdt.c b/drivers/watchdog/mpc8xxx_wdt.c
index 528bceb..eed5436 100644
--- a/drivers/watchdog/mpc8xxx_wdt.c
+++ b/drivers/watchdog/mpc8xxx_wdt.c
@@ -185,17 +185,20 @@ static struct miscdevice mpc8xxx_wdt_miscdev = {
 	.fops	= &mpc8xxx_wdt_fops,
 };
 
+static const struct of_device_id mpc8xxx_wdt_match[];
 static int __devinit mpc8xxx_wdt_probe(struct platform_device *ofdev)
 {
 	int ret;
+	const struct of_device_id *match;
 	struct device_node *np = ofdev->dev.of_node;
 	struct mpc8xxx_wdt_type *wdt_type;
 	u32 freq = fsl_get_sys_freq();
 	bool enabled;
 
-	if (!ofdev->dev.of_match)
+	match = of_match_device(mpc8xxx_wdt_match, &ofdev->dev);
+	if (!match)
 		return -EINVAL;
-	wdt_type = ofdev->dev.of_match->data;
+	wdt_type = match->data;
 
 	if (!freq || freq == -1)
 		return -EINVAL;
diff --git a/include/linux/device.h b/include/linux/device.h
index ab8dfc0..d08399d 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -442,7 +442,6 @@ struct device {
 	struct dev_archdata	archdata;
 
 	struct device_node	*of_node; /* associated device tree node */
-	const struct of_device_id *of_match; /* matching of_device_id from driver */
 
 	dev_t			devt;	/* dev_t, creates the sysfs "dev" */
 
diff --git a/include/linux/of_device.h b/include/linux/of_device.h
index b33d688..ae56384 100644
--- a/include/linux/of_device.h
+++ b/include/linux/of_device.h
@@ -21,12 +21,7 @@ extern void of_device_make_bus_id(struct device *dev);
 static inline int of_driver_match_device(struct device *dev,
 					 const struct device_driver *drv)
 {
-	const struct of_device_id *match;
-
-	match = of_match_device(drv->of_match_table, dev);
-	if (match)
-		dev->of_match = match;
-	return match != NULL;
+	return of_match_device(drv->of_match_table, dev) != NULL;
 }
 
 extern struct platform_device *of_dev_get(struct platform_device *dev);
@@ -62,6 +57,11 @@ static inline int of_device_uevent(struct device *dev,
 
 static inline void of_device_node_put(struct device *dev) { }
 
+static inline const struct of_device_id *of_match_device(
+		const struct of_device_id *matches, const struct device *dev)
+{
+	return NULL;
+}
 #endif /* CONFIG_OF_DEVICE */
 
 #endif /* _LINUX_OF_DEVICE_H */

Re: [PATCH 1/2] of: fix race when matching drivers

[Greg KH]

On Wed, May 18, 2011 at 01:21:00PM -0600, Grant Likely wrote:
> From: Milton Miller <miltonm@bga.com>
> 
> If two drivers are probing devices at the same time, both will write
> their match table result to the dev->of_match cache at the same time.
> 
> Only write the result if the device matches.
> 
> In a thread titled "SBus devices sometimes detected, sometimes not",
> Meelis reported his SBus hme was not detected about 50% of the time.
> >From the debug suggested by Grant it was obvious another driver matched
> some devices between the call to match the hme and the hme discovery
> failling.
> 
> Reported-by: Meelis Roos <mroos@linux.ee>
> Signed-off-by: Milton Miller <miltonm@bga.com>
> [grant.likely: modified to only call of_match_device() once]
> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

Acked-by: Greg Kroah-Hartman <gregkh@suse.de>

Re: [PATCH 2/2] drivercore: revert addition of of_match to struct device

[Greg KH]

On Wed, May 18, 2011 at 01:21:05PM -0600, Grant Likely wrote:
> Commit b826291c, "drivercore/dt: add a match table pointer to struct
> device" added an of_match pointer to struct device to cache the
> of_match_table entry discovered at driver match time.  This was unsafe
> because matching is not an atomic operation with probing a driver.  If
> two or more drivers are attempted to be matched to a driver at the
> same time, then the cached matching entry pointer could get
> overwritten.
> 
> This patch reverts the of_match cache pointer and reworks all users to
> call of_match_device() directly instead.
> 
> Signed-off-by: Grant Likely <grant.likely-s3s/WqlpOiPyB63q8FvJNQ@public.gmane.org>

Acked-by: Greg Kroah-Hartman <gregkh-l3A5Bk7waGM@public.gmane.org>

Re: [PATCH 1/2] of: fix race when matching drivers

[David Miller]

From: Grant Likely <grant.likely@secretlab.ca>
Date: Wed, 18 May 2011 13:21:00 -0600

> From: Milton Miller <miltonm@bga.com>
> 
> If two drivers are probing devices at the same time, both will write
> their match table result to the dev->of_match cache at the same time.
> 
> Only write the result if the device matches.
> 
> In a thread titled "SBus devices sometimes detected, sometimes not",
> Meelis reported his SBus hme was not detected about 50% of the time.
>>From the debug suggested by Grant it was obvious another driver matched
> some devices between the call to match the hme and the hme discovery
> failling.
> 
> Reported-by: Meelis Roos <mroos@linux.ee>
> Signed-off-by: Milton Miller <miltonm@bga.com>
> [grant.likely: modified to only call of_match_device() once]
> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

Tested on SunBlade2500 and Niagara2+

Acked-by: David S. Miller <davem@davemloft.net>

Re: [PATCH 2/2] drivercore: revert addition of of_match to struct device

[David Miller]

From: Grant Likely <grant.likely@secretlab.ca>
Date: Wed, 18 May 2011 13:21:05 -0600

> Commit b826291c, "drivercore/dt: add a match table pointer to struct
> device" added an of_match pointer to struct device to cache the
> of_match_table entry discovered at driver match time.  This was unsafe
> because matching is not an atomic operation with probing a driver.  If
> two or more drivers are attempted to be matched to a driver at the
> same time, then the cached matching entry pointer could get
> overwritten.
> 
> This patch reverts the of_match cache pointer and reworks all users to
> call of_match_device() directly instead.
> 
> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

Tested on SunBlade2500 and Niagara2+

Acked-by: David S. Miller <davem@davemloft.net>