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> --- drivers/ide/tx4938ide.c | 9 ++++++++- 1 files changed, 8 insertions(+), 1 deletions(-) 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) + shwt++; + if (shwt > 7) { + pr_warning("tx4938ide: SHWT violation (%d)\n", shwt); + shwt = 7; + } pr_debug("tx4938ide: ebus %d, bus cycle %dns, WT %d, SHWT %d\n", ebus_ch, cycle, wt, shwt); - __raw_writeq((cr & ~(0x3f007ull)) | (wt << 12) | shwt, + __raw_writeq((cr & ~0x3f007ull) | (wt << 12) | shwt, &tx4938_ebuscptr->cr[ebus_ch]); } -- 1.5.6.3 -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html