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* [PATCH] ata: pata_at91.c bugfix for high master clock
@ 2010-12-11  3:37 Igor Plyatov
  2010-12-11 18:40 ` Sergey Matyukevich
  0 siblings, 1 reply; 4+ messages in thread
From: Igor Plyatov @ 2010-12-11  3:37 UTC (permalink / raw)
  To: linux-arm-kernel

The AT91SAM9 microcontrollers with master clock higher then 105 MHz
and PIO0, have overflow of the NCS_RD_PULSE value in the MSB. This
lead to "NCS_RD_PULSE" pulse longer then "NRD_CYCLE" pulse and pata_at91
driver does not detect ATA device.

Signed-off-by: Igor Plyatov <plyatov@gmail.com>
---
 drivers/ata/pata_at91.c |   11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/ata/pata_at91.c b/drivers/ata/pata_at91.c
index 0da0dcc..2e189be 100644
--- a/drivers/ata/pata_at91.c
+++ b/drivers/ata/pata_at91.c
@@ -33,12 +33,14 @@
 
 
 #define DRV_NAME "pata_at91"
-#define DRV_VERSION "0.1"
+#define DRV_VERSION "0.2"
 
 #define CF_IDE_OFFSET	    0x00c00000
 #define CF_ALT_IDE_OFFSET   0x00e00000
 #define CF_IDE_RES_SIZE     0x08
 
+#define NCS_RD_PULSE_LIMIT  0x3f /* maximal value for pulse bitfields */
+
 struct at91_ide_info {
 	unsigned long mode;
 	unsigned int cs;
@@ -50,7 +52,7 @@ struct at91_ide_info {
 };
 
 static const struct ata_timing initial_timing =
-	{XFER_PIO_0, 70, 290, 240, 600, 165, 150, 600, 0};
+	{XFER_PIO_0, 70, 290, 240, 600, 165, 150, 0, 600, 0};
 
 static unsigned long calc_mck_cycles(unsigned long ns, unsigned long mck_hz)
 {
@@ -109,6 +111,11 @@ static void set_smc_timing(struct device *dev,
 	/* (CS0, CS1, DIR, OE) <= (CFCE1, CFCE2, CFRNW, NCSX) timings */
 	ncs_read_setup = 1;
 	ncs_read_pulse = read_cycle - 2;
+	if (ncs_read_pulse > NCS_RD_PULSE_LIMIT) {
+		ncs_read_pulse = NCS_RD_PULSE_LIMIT;
+		dev_dbg(dev, "ncs_read_pulse limited to maximal value %lu\n",
+			ncs_read_pulse);
+	}
 
 	/* Write timings same as read timings */
 	write_cycle = read_cycle;
-- 
1.7.0.4

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* [PATCH] ata: pata_at91.c bugfix for high master clock
  2010-12-11  3:37 [PATCH] ata: pata_at91.c bugfix for high master clock Igor Plyatov
@ 2010-12-11 18:40 ` Sergey Matyukevich
  2010-12-11 20:51   ` Igor Plyatov
  0 siblings, 1 reply; 4+ messages in thread
From: Sergey Matyukevich @ 2010-12-11 18:40 UTC (permalink / raw)
  To: linux-arm-kernel

Hello Igor,

On Sat, 11 Dec 2010 06:37:31 +0300
Igor Plyatov <plyatov@gmail.com> wrote:

> The AT91SAM9 microcontrollers with master clock higher then 105 MHz
> and PIO0, have overflow of the NCS_RD_PULSE value in the MSB. This
> lead to "NCS_RD_PULSE" pulse longer then "NRD_CYCLE" pulse and
> pata_at91 driver does not detect ATA device.
> 
> Signed-off-by: Igor Plyatov <plyatov@gmail.com>
> ---
>  drivers/ata/pata_at91.c |   11 +++++++++--
>  1 files changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/ata/pata_at91.c b/drivers/ata/pata_at91.c
> index 0da0dcc..2e189be 100644
> --- a/drivers/ata/pata_at91.c
> +++ b/drivers/ata/pata_at91.c
> @@ -33,12 +33,14 @@
>  
>  
>  #define DRV_NAME "pata_at91"
> -#define DRV_VERSION "0.1"
> +#define DRV_VERSION "0.2"
>  
>  #define CF_IDE_OFFSET	    0x00c00000
>  #define CF_ALT_IDE_OFFSET   0x00e00000
>  #define CF_IDE_RES_SIZE     0x08
>  
> +#define NCS_RD_PULSE_LIMIT  0x3f /* maximal value for pulse
> bitfields */ +
>  struct at91_ide_info {
>  	unsigned long mode;
>  	unsigned int cs;
> @@ -50,7 +52,7 @@ struct at91_ide_info {
>  };
>  
>  static const struct ata_timing initial_timing =
> -	{XFER_PIO_0, 70, 290, 240, 600, 165, 150, 600, 0};
> +	{XFER_PIO_0, 70, 290, 240, 600, 165, 150, 0, 600, 0};
>  
>  static unsigned long calc_mck_cycles(unsigned long ns, unsigned long
> mck_hz) {
> @@ -109,6 +111,11 @@ static void set_smc_timing(struct device *dev,
>  	/* (CS0, CS1, DIR, OE) <= (CFCE1, CFCE2, CFRNW, NCSX)
> timings */ ncs_read_setup = 1;
>  	ncs_read_pulse = read_cycle - 2;
> +	if (ncs_read_pulse > NCS_RD_PULSE_LIMIT) {
> +		ncs_read_pulse = NCS_RD_PULSE_LIMIT;
> +		dev_dbg(dev, "ncs_read_pulse limited to maximal
> value %lu\n",

arguably 'dev_warn' would be better in this case

> +			ncs_read_pulse);
> +	}
>  
>  	/* Write timings same as read timings */
>  	write_cycle = read_cycle;

Thanks for the fix.

By the way, it was not a good idea to send this patch separately to
both lists: linux-ide and linux-arm-kernel. I will ack this patch and
add linux-arm-kernel and other recipients in my reply to your email 
to linux-ide list.

Thanks,
Sergey

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH] ata: pata_at91.c bugfix for high master clock
       [not found] <1292011430-20835-1-git-send-email-plyatov@gmail.com>
@ 2010-12-11 19:16 ` Sergey Matyukevich
  0 siblings, 0 replies; 4+ messages in thread
From: Sergey Matyukevich @ 2010-12-11 19:16 UTC (permalink / raw)
  To: linux-arm-kernel

Hello Igor,

On Fri, 10 Dec 2010 23:03:50 +0300
Igor Plyatov <plyatov@gmail.com> wrote:

> The AT91SAM9 microcontrollers with master clock higher then 105 MHz
> and PIO0, have overflow of the NCS_RD_PULSE value in the MSB. This
> lead to "NCS_RD_PULSE" pulse longer then "NRD_CYCLE" pulse and
> pata_at91 driver does detect ATA device.
> 
> Signed-off-by: Igor Plyatov <plyatov@gmail.com>
> ---
>  drivers/ata/pata_at91.c |   11 +++++++++--
>  1 files changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/ata/pata_at91.c b/drivers/ata/pata_at91.c
> index 0da0dcc..2e189be 100644
> --- a/drivers/ata/pata_at91.c
> +++ b/drivers/ata/pata_at91.c
> @@ -33,12 +33,14 @@
>  
>  
>  #define DRV_NAME "pata_at91"
> -#define DRV_VERSION "0.1"
> +#define DRV_VERSION "0.2"
>  
>  #define CF_IDE_OFFSET	    0x00c00000
>  #define CF_ALT_IDE_OFFSET   0x00e00000
>  #define CF_IDE_RES_SIZE     0x08
>  
> +#define NCS_RD_PULSE_LIMIT  0x3f /* maximal value for pulse
> bitfields */ +
>  struct at91_ide_info {
>  	unsigned long mode;
>  	unsigned int cs;
> @@ -50,7 +52,7 @@ struct at91_ide_info {
>  };
>  
>  static const struct ata_timing initial_timing =
> -	{XFER_PIO_0, 70, 290, 240, 600, 165, 150, 600, 0};
> +	{XFER_PIO_0, 70, 290, 240, 600, 165, 150, 0, 600, 0};
>  
>  static unsigned long calc_mck_cycles(unsigned long ns, unsigned long
> mck_hz) {
> @@ -109,6 +111,11 @@ static void set_smc_timing(struct device *dev,
>  	/* (CS0, CS1, DIR, OE) <= (CFCE1, CFCE2, CFRNW, NCSX)
> timings */ ncs_read_setup = 1;
>  	ncs_read_pulse = read_cycle - 2;
> +	if (ncs_read_pulse > NCS_RD_PULSE_LIMIT) {
> +		ncs_read_pulse = NCS_RD_PULSE_LIMIT;
> +		dev_dbg(dev, "ncs_read_pulse limited to maximal

arguably 'dev_warn' would be more useful in this case

> value %lu\n",
> +			ncs_read_pulse);
> +	}
>  
>  	/* Write timings same as read timings */
>  	write_cycle = read_cycle;

Thanks for the fix.

Acked-by: Sergey Matyukevich <geomatsi@gmail.com>

Best regards,
Sergey

^ permalink raw reply	[flat|nested] 4+ messages in thread

* [PATCH] ata: pata_at91.c bugfix for high master clock
  2010-12-11 18:40 ` Sergey Matyukevich
@ 2010-12-11 20:51   ` Igor Plyatov
  0 siblings, 0 replies; 4+ messages in thread
From: Igor Plyatov @ 2010-12-11 20:51 UTC (permalink / raw)
  To: linux-arm-kernel

Dear Sergey,

> > @@ -109,6 +111,11 @@ static void set_smc_timing(struct device *dev,
> >  	/* (CS0, CS1, DIR, OE) <= (CFCE1, CFCE2, CFRNW, NCSX)
> > timings */ ncs_read_setup = 1;
> >  	ncs_read_pulse = read_cycle - 2;
> > +	if (ncs_read_pulse > NCS_RD_PULSE_LIMIT) {
> > +		ncs_read_pulse = NCS_RD_PULSE_LIMIT;
> > +		dev_dbg(dev, "ncs_read_pulse limited to maximal
> > value %lu\n",
> 
> arguably 'dev_warn' would be better in this case

Done as "PATCH v2".

Best regards!
--
Igor Plyatov

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2010-12-11 20:51 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2010-12-11  3:37 [PATCH] ata: pata_at91.c bugfix for high master clock Igor Plyatov
2010-12-11 18:40 ` Sergey Matyukevich
2010-12-11 20:51   ` Igor Plyatov
     [not found] <1292011430-20835-1-git-send-email-plyatov@gmail.com>
2010-12-11 19:16 ` Sergey Matyukevich

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