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authorIgor Plyatov <plyatov@gmail.com>2011-03-28 16:56:15 +0400
committerJeff Garzik <jgarzik@pobox.com>2011-04-24 11:34:06 -0400
commit9719b8f5bc35664a23de1ddfbc85217398af0df8 (patch)
tree5986b2a7bf9b990f92c3c11e10d37c3eb8d45d1a /drivers/ata
parent181e3ceaba761d35d96d791d5031b1e51abec46c (diff)
downloadlinux-9719b8f5bc35664a23de1ddfbc85217398af0df8.tar.gz
ata: pata_at91.c bugfix for high master clock
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 <plyatov@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>
Diffstat (limited to 'drivers/ata')
-rw-r--r--drivers/ata/pata_at91.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/ata/pata_at91.c b/drivers/ata/pata_at91.c
index 0da0dcc7dd08..a9a066a18ccf 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;
@@ -109,6 +110,11 @@ 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_warn(dev, "ncs_read_pulse limited to maximal value %lu\n",
+			ncs_read_pulse);
+	}
 
 	/* Write timings same as read timings */
 	write_cycle = read_cycle;