mtd: devices: elm: check for device's presence before configuration

PATCH Applied Daniel Mack 4 participants 6 messages Mar 3, 2013 – Mar 11, 2013

Subsystems (2)

Memory technology devices (MTD) NAND flash

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Daniel Mack

author

2013-03-03 23:57 UTC #0 lore raw

PATCH v2 1/1 mtd: devices: elm: check for device's presence before configuration

In case the driver is not probed - due to config mismatches or errors in the DTS files - dev_get_drvdata() returns NULL, leading to an Ooops during boot.

Make elm_config() return an error in such cases to propagate the error up to the user, so it can fall back to software mode.

Signed-off-by Daniel Mack <[email protected]>

Cc Philip Avinash <[email protected]>

Cc Artem Bityutskiy <[email protected]>

Cc Peter Korsgaard <[email protected]>

---
 drivers/mtd/devices/elm.c         | 9 ++++++++-
 drivers/mtd/nand/omap2.c          | 5 +++--
 include/linux/platform_data/elm.h | 2 +-
 3 files changed, 12 insertions(+), 4 deletions(-)

drivers/mtd/devices/elm.c +8 -1

index 2ec5da9..dccef9f 100644
@@ -81,14 +81,21 @@ static u32 elm_read_reg(struct elm_info *info, int offset)
  * @dev:	ELM device
  * @bch_type:	Type of BCH ecc
  */
-void elm_config(struct device *dev, enum bch_ecc bch_type)
+int elm_config(struct device *dev, enum bch_ecc bch_type)
 {
 	u32 reg_val;
 	struct elm_info *info = dev_get_drvdata(dev);
 
+	if (!info) {
+		dev_err(dev, "Unable to configure elm - device not probed?\n");
+		return -ENODEV;
+	}
+
 	reg_val = (bch_type & ECC_BCH_LEVEL_MASK) | (ELM_ECC_SIZE << 16);
 	elm_write_reg(info, ELM_LOCATION_CONFIG, reg_val);
 	info->bch_type = bch_type;
+
+	return 0;
 }
 EXPORT_SYMBOL(elm_config);

drivers/mtd/nand/omap2.c +3 -2

index 8e820dd..b97ef3b 100644
@@ -1701,8 +1701,9 @@ static int omap3_init_bch(struct mtd_info *mtd, int ecc_opt)
 		elm_node = of_find_node_by_phandle(be32_to_cpup(parp));
 		pdev = of_find_device_by_node(elm_node);
 		info->elm_dev = &pdev->dev;
-		elm_config(info->elm_dev, bch_type);
-		info->is_elm_used = true;
+
+		if (elm_config(info->elm_dev, bch_type) == 0)
+			info->is_elm_used = true;
 	}
 
 	if (info->is_elm_used && (mtd->writesize <= 4096)) {

include/linux/platform_data/elm.h +1 -1

index 1bd5244..bf0a83b 100644
@@ -50,5 +50,5 @@ struct elm_errorvec {
 
 void elm_decode_bch_error_page(struct device *dev, u8 *ecc_calc,
 		struct elm_errorvec *err_vec);
-void elm_config(struct device *dev, enum bch_ecc bch_type);
+int elm_config(struct device *dev, enum bch_ecc bch_type);
 #endif /* __ELM_H */

Signature · 1 line

1.8.1.4

Peter Korsgaard

Acked-by on v2 1/1

2013-03-04 07:48 UTC #1 lore raw

Quoted 1 line

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"Daniel" == Daniel Mack <[email protected]> writes:

Daniel> In case the driver is not probed - due to config mismatches or errors Daniel> in the DTS files - dev_get_drvdata() returns NULL, leading to an Ooops Daniel> during boot.

Daniel> Make elm_config() return an error in such cases to propagate the error Daniel> up to the user, so it can fall back to software mode.

Daniel> Signed-off-by: Daniel Mack <[email protected]> Daniel> Cc: Philip Avinash <[email protected]> Daniel> Cc: Artem Bityutskiy <[email protected]> Daniel> Cc: Peter Korsgaard <[email protected]>

Acked-by Peter Korsgaard <[email protected]>

Signature · 1 line

Bye, Peter Korsgaard

Daniel Mack

author

2013-03-05 10:24 UTC #2 lore raw

Quoted 9 lines · Peter Korsgaard

Quoted 1 line
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"Daniel" == Daniel Mack <[email protected]> writes:
Daniel> In case the driver is not probed - due to config mismatches or errors Daniel> in the DTS files - dev_get_drvdata() returns NULL, leading to an Ooops Daniel> during boot.
Daniel> Make elm_config() return an error in such cases to propagate the error Daniel> up to the user, so it can fall back to software mode.

Quoted 6 lines

Daniel> Signed-off-by: Daniel Mack <[email protected]> Daniel> Cc: Philip Avinash <[email protected]> Daniel> Cc: Artem Bityutskiy <[email protected]> Daniel> Cc: Peter Korsgaard <[email protected]>
Acked-by Peter Korsgaard <[email protected]>

Philip, are you also ok with this?

Thanks,
Daniel

Philip, Avinash

2013-03-05 10:27 UTC #3 lore raw

Quoted 10 lines · Daniel Mack

Quoted 9 lines · Peter Korsgaard
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"Daniel" == Daniel Mack <[email protected]> writes:
Daniel> In case the driver is not probed - due to config mismatches or errors Daniel> in the DTS files - dev_get_drvdata() returns NULL, leading to an Ooops Daniel> during boot.
Daniel> Make elm_config() return an error in such cases to propagate the error Daniel> up to the user, so it can fall back to software mode.

Quoted 8 lines

Quoted 6 lines
Daniel> Signed-off-by: Daniel Mack <[email protected]> Daniel> Cc: Philip Avinash <[email protected]> Daniel> Cc: Artem Bityutskiy <[email protected]> Daniel> Cc: Peter Korsgaard <[email protected]>
Acked-by Peter Korsgaard <[email protected]>
Philip, are you also ok with this?

Yes.
Thanks
Avinash

Quoted 6 lines

Thanks,
Daniel

Daniel Mack

author

2013-03-08 14:48 UTC #4 lore raw

Quoted 16 lines · Avinash

Quoted 15 lines · Daniel Mack
Quoted 14 lines · Peter Korsgaard
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"Daniel" == Daniel Mack <[email protected]> writes:
Daniel> In case the driver is not probed - due to config mismatches or errors Daniel> in the DTS files - dev_get_drvdata() returns NULL, leading to an Ooops Daniel> during boot.
Daniel> Make elm_config() return an error in such cases to propagate the error Daniel> up to the user, so it can fall back to software mode.
Daniel> Signed-off-by: Daniel Mack <[email protected]> Daniel> Cc: Philip Avinash <[email protected]> Daniel> Cc: Artem Bityutskiy <[email protected]> Daniel> Cc: Peter Korsgaard <[email protected]>

Quoted 7 lines

Quoted 3 lines
Quoted 1 line
Acked-by Peter Korsgaard <[email protected]>
Philip, are you also ok with this?
Yes.
Thanks
Avinash

Artem, can this go through your tree?

Thanks, everyone.

Daniel

Artem Bityutskiy

Applied

2013-03-11 09:18 UTC #5 lore raw

In reply to Daniel Mack

Quoted 8 lines · Daniel Mack

In case the driver is not probed - due to config mismatches or errors in the DTS files - dev_get_drvdata() returns NULL, leading to an Ooops during boot.
Make elm_config() return an error in such cases to propagate the error up to the user, so it can fall back to software mode.
Signed-off-by Daniel Mack <[email protected]>

Pushed to l2-mtd.git, thanks!

Signature · 2 lines

Best Regards,
Artem Bityutskiy