Re: [PATCH v3] ata: pata_at91.c bugfix for high master clock
From: Stanislaw Gruszka <stf_xl@wp.pl>
Date: 2011-03-28 19:30:09
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On Mon, Mar 28, 2011 at 03:59:55PM +0400, Igor Plyatov wrote:
quoted hunk ↗ jump to hunk
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 driver does not detect ATA device. Signed-off-by: Igor Plyatov <redacted> --- drivers/ata/pata_at91.c | 8 +++++++- 1 files changed, 7 insertions(+), 1 deletions(-)diff --git a/drivers/ata/pata_at91.c b/drivers/ata/pata_at91.c index d1aaeb5..3c2bf86 100644 --- a/drivers/ata/pata_at91.c +++ b/drivers/ata/pata_at91.c@@ -33,11 +33,12 @@ #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;@@ -110,6 +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;
It's ATA specification break, I explained this already here: http://marc.info/?l=linux-ide&m=129254321006232&w=2 Do we want fix that do not conform specification? Stanislaw