spi: fix mxc_spi_slave structure allocation to clear memory

PATCH New Matt Sealey 2 participants 6 messages Aug 17, 2012 – Aug 20, 2012

Subsystems (2)

Arm i.MX and Layerscape SPI

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Matt Sealey

author

2012-08-17 18:15 UTC #0 lore raw

PATCH 1/2 spi: fix mxc_spi_slave structure allocation to clear memory

Use calloc() instead of malloc() to allocate the mxc_spi_slave structure. Clearing the memory is necessary since most of the time this gets done super early in boot, but on warm reboots, and when SPI probing is done long after the init stages it could actually pick up previously used memory, and things like the chipselect polarity and other data end up being filled with trash data if not explicitly set by the board files.

This solves a semi-random, almost unreproducable error whereby SPI devices act very, very strangly on boot. Tested on Efika MX over several years..

Signed-off-by Matt Sealey <[email protected]>

---
 drivers/spi/mxc_spi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

drivers/spi/mxc_spi.c +1 -1

index 2e15318..d1dab18 100644
@@ -408,7 +408,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 	if (bus >= ARRAY_SIZE(spi_bases))
 		return NULL;
 
-	mxcs = malloc(sizeof(struct mxc_spi_slave));
+	mxcs = calloc(sizeof(struct mxc_spi_slave), 1);
 	if (!mxcs) {
 		puts("mxc_spi: SPI Slave not allocated !\n");
 		return NULL;

Signature · 1 line

1.7.9.5

Matt Sealey

author

2012-08-17 18:15 UTC #1 lore raw

PATCH 2/2 spi: fix mxs_spi_slave structure allocation to clear memory

Use calloc() instead of malloc() to allocate the mxs_spi_slave structure. Clearing the memory is necessary since most of the time this gets done super early in boot, but on warm reboots, and when SPI probing is done long after the init stages it could actually pick up previously used memory, and things like the chipselect polarity and other data end up being filled with trash data if not explicitly set by the board files.

This solves a semi-random, almost unreproducable error whereby SPI devices act very, very strangly on boot.

Signed-off-by Matt Sealey <[email protected]>

---
 drivers/spi/mxs_spi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

drivers/spi/mxs_spi.c +1 -1

index a037c13..5fa7f2b 100644
@@ -91,7 +91,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 		return NULL;
 	}
 
-	mxs_slave = malloc(sizeof(struct mxs_spi_slave));
+	mxs_slave = calloc(sizeof(struct mxs_spi_slave), 1);
 	if (!mxs_slave)
 		return NULL;

Signature · 1 line

1.7.9.5

stefano babic

2012-08-18 09:05 UTC #2 lore raw

PATCH 2/2 spi: fix mxs_spi_slave structure allocation to clear memory

Am 17/08/2012 20:15, schrieb Matt Sealey:

Quoted 21 lines

Use calloc() instead of malloc() to allocate the mxs_spi_slave structure. Clearing the memory is necessary since most of the time this gets done super early in boot, but on warm reboots, and when SPI probing is done long after the init stages it could actually pick up previously used memory, and things like the chipselect polarity and other data end up being filled with trash data if not explicitly set by the board files.
This solves a semi-random, almost unreproducable error whereby SPI devices act very, very strangly on boot.
Signed-off-by Matt Sealey <[email protected]>
---
 drivers/spi/mxs_spi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/spi/mxs_spi.c +0 -0
index a037c13..5fa7f2b 100644

drivers/spi/mxs_spi.c struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, · line 97

Quoted 8 lines

drivers/spi/mxs_spi.c +1 -1

@@ -91,7 +91,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 		return NULL;
 	}
 
-	mxs_slave = malloc(sizeof(struct mxs_spi_slave));
+	mxs_slave = calloc(sizeof(struct mxs_spi_slave), 1);
 	if (!mxs_slave)
 		return NULL;

Acked-by Stefano Babic <[email protected]>

Best regards,
Stefano Babic

Signature · 5 lines

=====================================================================
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80  Email: office at denx.de
=====================================================================

Stefano Babic

2012-08-20 07:59 UTC #3 lore raw

PATCH 2/2 spi: fix mxs_spi_slave structure allocation to clear memory

In reply to Matt Sealey

Quoted 21 lines · Matt Sealey

Use calloc() instead of malloc() to allocate the mxs_spi_slave structure. Clearing the memory is necessary since most of the time this gets done super early in boot, but on warm reboots, and when SPI probing is done long after the init stages it could actually pick up previously used memory, and things like the chipselect polarity and other data end up being filled with trash data if not explicitly set by the board files.
This solves a semi-random, almost unreproducable error whereby SPI devices act very, very strangly on boot.
Signed-off-by Matt Sealey <[email protected]>
---
 drivers/spi/mxs_spi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/spi/mxs_spi.c +0 -0
index a037c13..5fa7f2b 100644

drivers/spi/mxs_spi.c struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, · line 97

Quoted 8 lines

drivers/spi/mxs_spi.c +1 -1

@@ -91,7 +91,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 		return NULL;
 	}
 
-	mxs_slave = malloc(sizeof(struct mxs_spi_slave));
+	mxs_slave = calloc(sizeof(struct mxs_spi_slave), 1);
 	if (!mxs_slave)
 		return NULL;

Applied to u-boot-imx, thanks.

Best regards,
Stefano Babic

Signature · 5 lines

=====================================================================
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic at denx.de
=====================================================================

stefano babic

2012-08-18 09:05 UTC #4 lore raw

PATCH 1/2 spi: fix mxc_spi_slave structure allocation to clear memory

In reply to Matt Sealey

Am 17/08/2012 20:15, schrieb Matt Sealey:

Quoted 21 lines

Use calloc() instead of malloc() to allocate the mxc_spi_slave structure. Clearing the memory is necessary since most of the time this gets done super early in boot, but on warm reboots, and when SPI probing is done long after the init stages it could actually pick up previously used memory, and things like the chipselect polarity and other data end up being filled with trash data if not explicitly set by the board files.
This solves a semi-random, almost unreproducable error whereby SPI devices act very, very strangly on boot. Tested on Efika MX over several years..
Signed-off-by Matt Sealey <[email protected]>
---
 drivers/spi/mxc_spi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/spi/mxc_spi.c +0 -0
index 2e15318..d1dab18 100644

drivers/spi/mxc_spi.c struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, · line 414

Quoted 8 lines

drivers/spi/mxc_spi.c +1 -1

@@ -408,7 +408,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 	if (bus >= ARRAY_SIZE(spi_bases))
 		return NULL;
 
-	mxcs = malloc(sizeof(struct mxc_spi_slave));
+	mxcs = calloc(sizeof(struct mxc_spi_slave), 1);
 	if (!mxcs) {
 		puts("mxc_spi: SPI Slave not allocated !\n");
 		return NULL;

Agree, the structure must be zeroed.

Acked-by Stefano Babic <[email protected]>

Best regards,
Stefano Babic

Signature · 5 lines

=====================================================================
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-0 Fax: +49-8142-66989-80  Email: office at denx.de
=====================================================================

Stefano Babic

2012-08-20 07:59 UTC #5 lore raw

PATCH 1/2 spi: fix mxc_spi_slave structure allocation to clear memory

In reply to Matt Sealey

Quoted 21 lines · Matt Sealey

Use calloc() instead of malloc() to allocate the mxc_spi_slave structure. Clearing the memory is necessary since most of the time this gets done super early in boot, but on warm reboots, and when SPI probing is done long after the init stages it could actually pick up previously used memory, and things like the chipselect polarity and other data end up being filled with trash data if not explicitly set by the board files.
This solves a semi-random, almost unreproducable error whereby SPI devices act very, very strangly on boot. Tested on Efika MX over several years..
Signed-off-by Matt Sealey <[email protected]>
---
 drivers/spi/mxc_spi.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/spi/mxc_spi.c +0 -0
index 2e15318..d1dab18 100644

drivers/spi/mxc_spi.c struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, · line 414

Quoted 8 lines

drivers/spi/mxc_spi.c +1 -1

@@ -408,7 +408,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
 	if (bus >= ARRAY_SIZE(spi_bases))
 		return NULL;
 
-	mxcs = malloc(sizeof(struct mxc_spi_slave));
+	mxcs = calloc(sizeof(struct mxc_spi_slave), 1);
 	if (!mxcs) {
 		puts("mxc_spi: SPI Slave not allocated !\n");
 		return NULL;

Applied to u-boot-imx, thanks.

Best regards,
Stefano Babic

Signature · 5 lines

=====================================================================
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-53 Fax: +49-8142-66989-80 Email: sbabic at denx.de
=====================================================================