From: Ondrej Zary linux@zary.sk
[ 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@zary.sk Reviewed-by: Sergey Shtylyov s.shtylyov@omp.ru Signed-off-by: Damien Le Moal dlemoal@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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: