[PATCH 1/1] spi: Fix "not ready" timeout after write in at25.

[PATCH 1/1] spi: Fix "not ready" timeout after write in at25.

[Sebastian Heutling]

Under certain circumstances msleep(1) within the loop, which waits
for the EEPROM to be finished, might take longer than the timeout.
On the next loop the status register might now return to be ready
and therefore the loop finishes. The following check now tests if
a timeout occurred and if so returns an error although the device
reported to have finished.
This fix replaces testing the occurrence of the timeout by testing
the "not ready" bit in the status register.
The patch is against 2.6.29.2.

Signed-off-by: Sebastian Heutling <heutling-U9zb0o/1OQCELgA04lAiVw@public.gmane.org> 

---
 drivers/misc/eeprom/at25.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c
index 290dbe9..ea83604 100644
--- a/drivers/misc/eeprom/at25.c
+++ b/drivers/misc/eeprom/at25.c
@@ -160,6 +160,7 @@ at25_ee_write(struct at25_data *at25, char *buf, loff_t off, size_t count)
 	bounce[0] = AT25_WRITE;
 	mutex_lock(&at25->lock);
 	do {
+		int	sr;
 		unsigned long	timeout, retries;
 		unsigned	segment;
 		unsigned	offset = (unsigned) off;
@@ -205,7 +206,6 @@ at25_ee_write(struct at25_data *at25, char *buf, loff_t off, size_t count)
 		timeout = jiffies + msecs_to_jiffies(EE_TIMEOUT);
 		retries = 0;
 		do {
-			int	sr;
 
 			sr = spi_w8r8(at25->spi, AT25_RDSR);
 			if (sr < 0 || (sr & AT25_SR_nRDY)) {
@@ -219,7 +219,7 @@ at25_ee_write(struct at25_data *at25, char *buf, loff_t off, size_t count)
 				break;
 		} while (retries++ < 3 || time_before_eq(jiffies, timeout));
 
-		if (time_after(jiffies, timeout)) {
+		if ((sr < 0) || (sr & AT25_SR_nRDY)) {
 			dev_err(&at25->spi->dev,
 				"write %d bytes offset %d, "
 				"timeout after %u msecs\n",
-- 
1.6.3.2


------------------------------------------------------------------------------

Re: [PATCH 1/1] spi: Fix "not ready" timeout after write in at25

[David Brownell]

On Monday 08 June 2009, Sebastian Heutling wrote:
> Under certain circumstances msleep(1) within the loop, which waits
> for the EEPROM to be finished, might take longer than the timeout.
> On the next loop the status register might return to be ready and 
> therefore the loop finishes. The following check now tests if
> a timeout occurred and if so returns an error although the device
> reported to be finished.
> This fix replaces testing the occurrence of the timeout by testing
> the "not ready" bit in the status register.
> The patch is against 2.6.29.2.

This got badly mangled by your mailer.  Care to re-send?

> 
> Signed-off-by: Sebastian Heutling <heutling-U9zb0o/1OQCELgA04lAiVw@public.gmane.org>
> 
> ---
>   drivers/misc/eeprom/at25.c |    4 ++--
>   1 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c
> index 290dbe9..ea83604 100644
> --- a/drivers/misc/eeprom/at25.c
> +++ b/drivers/misc/eeprom/at25.c
> @@ -160,6 +160,7 @@ at25_ee_write(struct at25_data *at25, char *buf, 
> loff_t off, size_t count)
>   	bounce[0] = AT25_WRITE;
>   	mutex_lock(&at25->lock);
>   	do {
> +		int	sr;
>   		unsigned long	timeout, retries;
>   		unsigned	segment;
>   		unsigned	offset = (unsigned) off;
> @@ -205,7 +206,6 @@ at25_ee_write(struct at25_data *at25, char *buf, 
> loff_t off, size_t count)
>   		timeout = jiffies + msecs_to_jiffies(EE_TIMEOUT);
>   		retries = 0;
>   		do {
> -			int	sr;
>    			sr = spi_w8r8(at25->spi, AT25_RDSR);
>   			if (sr < 0 || (sr & AT25_SR_nRDY)) {
> @@ -219,7 +219,7 @@ at25_ee_write(struct at25_data *at25, char *buf, 
> loff_t off, size_t count)
>   				break;
>   		} while (retries++ < 3 || time_before_eq(jiffies, timeout));
>   -		if (time_after(jiffies, timeout)) {
> +		if ((sr < 0) || (sr & AT25_SR_nRDY)) {
>   			dev_err(&at25->spi->dev,
>   				"write %d bytes offset %d, "
>   				"timeout after %u msecs\n",
> -- 
> 1.6.3.2

------------------------------------------------------------------------------

[PATCH 1/1] spi: Fix "not ready" timeout after write in at25

[Sebastian Heutling]

Under certain circumstances msleep(1) within the loop, which waits
for the EEPROM to be finished, might take longer than the timeout.
On the next loop the status register might return to be ready and 
therefore the loop finishes. The following check now tests if
a timeout occurred and if so returns an error although the device
reported to be finished.
This fix replaces testing the occurrence of the timeout by testing
the "not ready" bit in the status register.
The patch is against 2.6.29.2.

Signed-off-by: Sebastian Heutling <heutling-U9zb0o/1OQCELgA04lAiVw@public.gmane.org>

---
  drivers/misc/eeprom/at25.c |    4 ++--
  1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/misc/eeprom/at25.c b/drivers/misc/eeprom/at25.c
index 290dbe9..ea83604 100644
--- a/drivers/misc/eeprom/at25.c
+++ b/drivers/misc/eeprom/at25.c
@@ -160,6 +160,7 @@ at25_ee_write(struct at25_data *at25, char *buf, 
loff_t off, size_t count)
  	bounce[0] = AT25_WRITE;
  	mutex_lock(&at25->lock);
  	do {
+		int	sr;
  		unsigned long	timeout, retries;
  		unsigned	segment;
  		unsigned	offset = (unsigned) off;
@@ -205,7 +206,6 @@ at25_ee_write(struct at25_data *at25, char *buf, 
loff_t off, size_t count)
  		timeout = jiffies + msecs_to_jiffies(EE_TIMEOUT);
  		retries = 0;
  		do {
-			int	sr;
   			sr = spi_w8r8(at25->spi, AT25_RDSR);
  			if (sr < 0 || (sr & AT25_SR_nRDY)) {
@@ -219,7 +219,7 @@ at25_ee_write(struct at25_data *at25, char *buf, 
loff_t off, size_t count)
  				break;
  		} while (retries++ < 3 || time_before_eq(jiffies, timeout));
  -		if (time_after(jiffies, timeout)) {
+		if ((sr < 0) || (sr & AT25_SR_nRDY)) {
  			dev_err(&at25->spi->dev,
  				"write %d bytes offset %d, "
  				"timeout after %u msecs\n",
-- 
1.6.3.2


------------------------------------------------------------------------------
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