| Message ID | 1292011430-20835-1-git-send-email-plyatov@gmail.com |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
Here is a typo in the patch description: > 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. "...driver DOES NOT detect ATA device." -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Dear Sergei, > > I do not test this driver, but I think it have the same problem, because > > it have the same algorithm for timings calculation. > > I quickly looked thru both drivers and the algorithm seemed different. :-) I don't think so... > > If you will see "cycle" value greater then 63, then problem exists. > > I thought the problem was with active pulse width, not total cycle time... The problem was - the same "cycle" variable used to set up NRD_CYCLE (max value = 127) and NCS_RD_PULSE (max value = 63). Where NRD_CYCLE, NCS_RD_PULSE names from datasheet for AT91SAM9. If NCS_RD_PULSE > 63, then overflow occur and pulse is much longer then required. For the 132 MHz, driver use NCS_RD_PULSE = 80 at device detection moment on my board. Calculated cycle in at91_ide is the same as for pata_at91 driver. > > Generally, I does not see any reasons to use at91_ide, because ATA > > drivers subsystem going to replace IDE drivers. > > There may be reasons -- like larger thruput in PIO mode (you have to check > this though -- but generally libata seems very slow in PIO). Anyway, it > doesn't mean that the bugs in IDE drivers should be ignored, and the > replacemtn will not happen anytime soon (not all IDE drivers are ported to > libata yet). I will send next patch where this driver corrected and tested. Best regards! -- Igor Plyatov -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hello. On 11-12-2010 22:43, Igor Plyatov wrote: >>> I do not test this driver, but I think it have the same problem, because >>> it have the same algorithm for timings calculation. >> I quickly looked thru both drivers and the algorithm seemed different. :-) > I don't think so... In fact, the algorithm is slightly different. >>> If you will see "cycle" value greater then 63, then problem exists. >> I thought the problem was with active pulse width, not total cycle time... > The problem was - the same "cycle" variable used to set up NRD_CYCLE > (max value = 127) and NCS_RD_PULSE (max value = 63). > Where NRD_CYCLE, NCS_RD_PULSE names from datasheet for AT91SAM9. > If NCS_RD_PULSE > 63, then overflow occur and pulse is much longer then > required. Ah, NCS_RD_PULSE is different from active pulse time which is in the variable 'nrd_pulse'. > For the 132 MHz, driver use NCS_RD_PULSE = 80 at device detection moment > on my board. > Calculated cycle in at91_ide is the same as for pata_at91 driver. Yes, but NCS_RD_PULSE is different in these drivers, it's cycle_time in at91_ide.c and (cycle time - 2) in the pata_at91.c... Then there should indeed be an error in at91_ide.c as well. >>> Generally, I does not see any reasons to use at91_ide, because ATA >>> drivers subsystem going to replace IDE drivers. >> There may be reasons -- like larger thruput in PIO mode (you have to check >> this though -- but generally libata seems very slow in PIO). Anyway, it >> doesn't mean that the bugs in IDE drivers should be ignored, and the >> replacemtn will not happen anytime soon (not all IDE drivers are ported to >> libata yet). > I will send next patch where this driver corrected and tested. Thanks. :-) > Best regards! > -- > Igor Plyatov WBR, Sergei -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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;
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(-)