From: Ondrej Zary <linux@xxxxxxx>
[ Upstream commit 0c1e81d0b5ebd5813536dd5fcf5966ad043f37dc ]
fit3 protocol driver does not support accessing IDE control registers
(device control/altstatus). The DOS driver does not use these registers
either (as observed from DOSEMU trace). But the HW seems to be capable
of accessing these registers - I simply tried bit 3 and it works!
The control register is required to properly reset ATAPI devices or
they will be detected only once (after a power cycle).
Tested with EXP Computer CD-865 with MC-1285B EPP cable and
TransDisk 3000.
Signed-off-by: Ondrej Zary <linux@xxxxxxx>
Reviewed-by: Sergey Shtylyov <s.shtylyov@xxxxxx>
Signed-off-by: Damien Le Moal <dlemoal@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/ata/pata_parport/fit3.c | 14 ++------------
1 file changed, 2 insertions(+), 12 deletions(-)
diff --git a/drivers/ata/pata_parport/fit3.c b/drivers/ata/pata_parport/fit3.c
index bad7aa920cdca..d2b81cf2e16d2 100644
--- a/drivers/ata/pata_parport/fit3.c
+++ b/drivers/ata/pata_parport/fit3.c
@@ -9,11 +9,6 @@
*
* The TD-2000 and certain older devices use a different protocol.
* Try the fit2 protocol module with them.
- *
- * NB: The FIT adapters do not appear to support the control
- * registers. So, we map ALT_STATUS to STATUS and NO-OP writes
- * to the device control register - this means that IDE reset
- * will not work on these devices.
*/
#include <linux/module.h>
@@ -37,8 +32,7 @@
static void fit3_write_regr(struct pi_adapter *pi, int cont, int regr, int val)
{
- if (cont == 1)
- return;
+ regr += cont << 3;
switch (pi->mode) {
case 0:
@@ -59,11 +53,7 @@ static int fit3_read_regr(struct pi_adapter *pi, int cont, int regr)
{
int a, b;
- if (cont) {
- if (regr != 6)
- return 0xff;
- regr = 7;
- }
+ regr += cont << 3;
switch (pi->mode) {
case 0:
--
2.40.1
