Hello.
Atsushi Nemoto wrote:
SHWT value is used as address valid to -CSx assertion and -CSx to -DIOx
assertion setup time, and contrarywise, -DIOx to -CSx release and -CSx
release to address invalid hold time, so it actualy applies 4 times and
so constitutes -DIOx recovery time. Check requirement of the recovery
time and cycle time. Also check SHWT maximum value.
Suggested-by: Sergei Shtylyov <sshtylyov@xxxxxxxxxxxxx>
Signed-off-by: Atsushi Nemoto <anemo@xxxxxxxxxxxxx>
diff --git a/drivers/ide/tx4938ide.c b/drivers/ide/tx4938ide.c
index fa660f9..7e4820e 100644
--- a/drivers/ide/tx4938ide.c
+++ b/drivers/ide/tx4938ide.c
@@ -39,10 +39,17 @@ static void tx4938ide_tune_ebusc(unsigned int ebus_ch,
/* Address-valid to DIOR/DIOW setup */
shwt = DIV_ROUND_UP(t->setup, cycle);
+ /* -DIOx recovery time (SHWT * 4) and cycle time requirement */
+ while (shwt * cycle * 4 + t->act8b < t->cycle)
This can lead to adding an extra setup cycle due to use of "non-quantized"
active time, here's more precise expression for the cycle time:
(shwt * 4 + wt + (wt ? 2 : 3)) * cycle
or even this, more obsure:
(shwt * 4 + wt + !wt + 2) * cycle
MBR, Sergei
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