[PATCH v2 0/3] mmc: cavium: bug fixes for 4.12

[PATCH v2 0/3] mmc: cavium: bug fixes for 4.12

[Jan Glauber]

Changes to v1:
- Fixed platform device leak, apply fix also to Octeon driver
- Use mmc_regulator_get_supply

Jan Glauber (3):
  mmc: cavium: Prevent crash with incomplete DT
  of/platform: Make of_platform_device_destroy globally visible
  mmc: cavium: Fix probing race with regulator

 drivers/mmc/host/cavium-octeon.c   | 11 ++++++++++-
 drivers/mmc/host/cavium-thunderx.c |  6 ++++++
 drivers/mmc/host/cavium.c          | 25 ++++++++++---------------
 drivers/of/platform.c              |  3 ++-
 include/linux/of_platform.h        |  1 +
 5 files changed, 29 insertions(+), 17 deletions(-)

-- 
2.9.0.rc0.21.g7777322

[PATCH v2 1/3] mmc: cavium: Prevent crash with incomplete DT

[Jan Glauber]

In case the DT specifies neither a regulator nor a gpio
for the shared power the driver will crash accessing the regulator.
Prevent the crash by checking the regulator before use.

Use mmc_regulator_get_supply() instead of open coding the same
logic.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
 drivers/mmc/host/cavium.c | 25 ++++++++++---------------
 1 file changed, 10 insertions(+), 15 deletions(-)

diff --git a/drivers/mmc/host/cavium.c b/drivers/mmc/host/cavium.c
index 58b51ba..b8aaf0f 100644
--- a/drivers/mmc/host/cavium.c
+++ b/drivers/mmc/host/cavium.c
@@ -839,14 +839,14 @@ static void cvm_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 		cvm_mmc_reset_bus(slot);
 		if (host->global_pwr_gpiod)
 			host->set_shared_power(host, 0);
-		else
+		else if (!IS_ERR(mmc->supply.vmmc))
 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, 0);
 		break;
 
 	case MMC_POWER_UP:
 		if (host->global_pwr_gpiod)
 			host->set_shared_power(host, 1);
-		else
+		else if (!IS_ERR(mmc->supply.vmmc))
 			mmc_regulator_set_ocr(mmc, mmc->supply.vmmc, ios->vdd);
 		break;
 	}
@@ -968,20 +968,15 @@ static int cvm_mmc_of_parse(struct device *dev, struct cvm_mmc_slot *slot)
 		return -EINVAL;
 	}
 
-	mmc->supply.vmmc = devm_regulator_get_optional(dev, "vmmc");
-	if (IS_ERR(mmc->supply.vmmc)) {
-		if (PTR_ERR(mmc->supply.vmmc) == -EPROBE_DEFER)
-			return -EPROBE_DEFER;
-		/*
-		 * Legacy Octeon firmware has no regulator entry, fall-back to
-		 * a hard-coded voltage to get a sane OCR.
-		 */
+	ret = mmc_regulator_get_supply(mmc);
+	if (ret == -EPROBE_DEFER)
+		return ret;
+	/*
+	 * Legacy Octeon firmware has no regulator entry, fall-back to
+	 * a hard-coded voltage to get a sane OCR.
+	 */
+	if (IS_ERR(mmc->supply.vmmc))
 		mmc->ocr_avail = MMC_VDD_32_33 | MMC_VDD_33_34;
-	} else {
-		ret = mmc_regulator_get_ocrmask(mmc->supply.vmmc);
-		if (ret > 0)
-			mmc->ocr_avail = ret;
-	}
 
 	/* Common MMC bindings */
 	ret = mmc_of_parse(mmc);
-- 
2.9.0.rc0.21.g7777322

[PATCH v2 2/3] of/platform: Make of_platform_device_destroy globally visible

[Jan Glauber]

of_platform_device_destroy is the counterpart to
of_platform_device_create which is a non-static function.

After creating a platform device it might be neccessary
to destroy it to deal with -EPROBE_DEFER where a
repeated of_platform_device_create call would fail otherwise.

Therefore also make of_platform_device_destroy globally visible.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
 drivers/of/platform.c       | 3 ++-
 include/linux/of_platform.h | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 71fecc2..703a421 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -523,7 +523,7 @@ static int __init of_platform_default_populate_init(void)
 arch_initcall_sync(of_platform_default_populate_init);
 #endif
 
-static int of_platform_device_destroy(struct device *dev, void *data)
+int of_platform_device_destroy(struct device *dev, void *data)
 {
 	/* Do not touch devices not populated from the device tree */
 	if (!dev->of_node || !of_node_check_flag(dev->of_node, OF_POPULATED))
@@ -544,6 +544,7 @@ static int of_platform_device_destroy(struct device *dev, void *data)
 	of_node_clear_flag(dev->of_node, OF_POPULATED_BUS);
 	return 0;
 }
+EXPORT_SYMBOL_GPL(of_platform_device_destroy);
 
 /**
  * of_platform_depopulate() - Remove devices populated from device tree
diff --git a/include/linux/of_platform.h b/include/linux/of_platform.h
index dc8224a..e0d1946 100644
--- a/include/linux/of_platform.h
+++ b/include/linux/of_platform.h
@@ -64,6 +64,7 @@ extern struct platform_device *of_platform_device_create(struct device_node *np,
 						   const char *bus_id,
 						   struct device *parent);
 
+extern int of_platform_device_destroy(struct device *dev, void *data);
 extern int of_platform_bus_probe(struct device_node *root,
 				 const struct of_device_id *matches,
 				 struct device *parent);
-- 
2.9.0.rc0.21.g7777322

[PATCH v2 3/3] mmc: cavium: Fix probing race with regulator

[Jan Glauber]

If the regulator probing is not yet finished this driver
might catch a -EPROBE_DEFER. Returning after this condition
did not remove the created platform device. On a repeated
call to the probe function the of_platform_device_create
fails.

Calling of_platform_device_destroy after EPROBE_DEFER resolves
this bug.

Signed-off-by: Jan Glauber <jglauber@cavium.com>
---
 drivers/mmc/host/cavium-octeon.c   | 11 ++++++++++-
 drivers/mmc/host/cavium-thunderx.c |  6 ++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/cavium-octeon.c b/drivers/mmc/host/cavium-octeon.c
index cbb5663..951d2cd 100644
--- a/drivers/mmc/host/cavium-octeon.c
+++ b/drivers/mmc/host/cavium-octeon.c
@@ -288,11 +288,20 @@ static int octeon_mmc_probe(struct platform_device *pdev)
 		if (ret) {
 			dev_err(&pdev->dev, "Error populating slots\n");
 			octeon_mmc_set_shared_power(host, 0);
-			return ret;
+			goto error;
 		}
 		i++;
 	}
 	return 0;
+
+error:
+	for (i = 0; i < CAVIUM_MAX_MMC; i++) {
+		if (host->slot[i])
+			cvm_mmc_of_slot_remove(host->slot[i]);
+		if (host->slot_pdev[i])
+			of_platform_device_destroy(&host->slot_pdev[i]->dev, NULL);
+	}
+	return ret;
 }
 
 static int octeon_mmc_remove(struct platform_device *pdev)
diff --git a/drivers/mmc/host/cavium-thunderx.c b/drivers/mmc/host/cavium-thunderx.c
index fe3d772..b9cc959 100644
--- a/drivers/mmc/host/cavium-thunderx.c
+++ b/drivers/mmc/host/cavium-thunderx.c
@@ -146,6 +146,12 @@ static int thunder_mmc_probe(struct pci_dev *pdev,
 	return 0;
 
 error:
+	for (i = 0; i < CAVIUM_MAX_MMC; i++) {
+		if (host->slot[i])
+			cvm_mmc_of_slot_remove(host->slot[i]);
+		if (host->slot_pdev[i])
+			of_platform_device_destroy(&host->slot_pdev[i]->dev, NULL);
+	}
 	clk_disable_unprepare(host->clk);
 	return ret;
 }
-- 
2.9.0.rc0.21.g7777322

Re: [PATCH v2 2/3] of/platform: Make of_platform_device_destroy globally visible

[Rob Herring]

On Mon, May 22, 2017 at 6:09 AM, Jan Glauber <jglauber@cavium.com> wrote:
> of_platform_device_destroy is the counterpart to
> of_platform_device_create which is a non-static function.
>
> After creating a platform device it might be neccessary
> to destroy it to deal with -EPROBE_DEFER where a
> repeated of_platform_device_create call would fail otherwise.
>
> Therefore also make of_platform_device_destroy globally visible.
>
> Signed-off-by: Jan Glauber <jglauber@cavium.com>
> ---
>  drivers/of/platform.c       | 3 ++-
>  include/linux/of_platform.h | 1 +
>  2 files changed, 3 insertions(+), 1 deletion(-)

Acked-by: Rob Herring <robh@kernel.org>

Re: [PATCH v2 0/3] mmc: cavium: bug fixes for 4.12

[Ulf Hansson]

On 22 May 2017 at 13:09, Jan Glauber <jglauber@cavium.com> wrote:
> Changes to v1:
> - Fixed platform device leak, apply fix also to Octeon driver
> - Use mmc_regulator_get_supply
>
> Jan Glauber (3):
>   mmc: cavium: Prevent crash with incomplete DT
>   of/platform: Make of_platform_device_destroy globally visible
>   mmc: cavium: Fix probing race with regulator
>
>  drivers/mmc/host/cavium-octeon.c   | 11 ++++++++++-
>  drivers/mmc/host/cavium-thunderx.c |  6 ++++++
>  drivers/mmc/host/cavium.c          | 25 ++++++++++---------------
>  drivers/of/platform.c              |  3 ++-
>  include/linux/of_platform.h        |  1 +
>  5 files changed, 29 insertions(+), 17 deletions(-)
>
> --
> 2.9.0.rc0.21.g7777322
>

Thanks, applied for fixes!

Kind regards
Uffe