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Message-Id: <20231005192440.4047-5-linux@zary.sk>
Date: Thu, 5 Oct 2023 21:24:40 +0200
From: Ondrej Zary <linux@...y.sk>
To: Damien Le Moal <dlemoal@...nel.org>,
Sudip Mukherjee <sudipm.mukherjee@...il.com>
Cc: Christoph Hellwig <hch@....de>,
Sergey Shtylyov <s.shtylyov@....ru>,
Tim Waugh <tim@...erelk.net>,
linux-parport@...ts.infradead.org, linux-ide@...r.kernel.org,
linux-kernel@...r.kernel.org
Subject: [PATCH 4/4] ata: pata_parport: fit3: implement IDE command set registers
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@...y.sk>
---
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 bad7aa920cdc..d2b81cf2e16d 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:
--
Ondrej Zary
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