From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D9128E936EC for ; Wed, 4 Oct 2023 22:43:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236972AbjJDWnJ (ORCPT ); Wed, 4 Oct 2023 18:43:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56532 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233822AbjJDWnH (ORCPT ); Wed, 4 Oct 2023 18:43:07 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 73C0EC9; Wed, 4 Oct 2023 15:43:03 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 09409C433C7; Wed, 4 Oct 2023 22:43:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1696459383; bh=xiFYyd2cMCEdaqtSn5Y6qReiUUe9LSLHDqPkOd4T3mc=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=GCOAAS+P7+NvLI5JaKLawgdhMJp0ItYh/ofLWCIpsZXt1uNTpoa8JQFsPWFTYnFYH F+pHT/mYsD/C9LfDu/L5smS2kOYuZXgJ4Kpn66xLLxLtNVXMYROPp60feChJvIx4IU 60a0kcd1Y2oH0BBH+/D4TPMx9KKGq5lbdPnRgNGlZLn5fsW+E5yt321jjgx2xbQDYW YSxT1zeijL81hxYMoKkN7bpSL9wIwbjnIOqa+WwuWTyelfgWkSGuyBm2LzFY/XVxLb 3T7osJ3DGW+nTHbwBpDKbroIMx69pRuRw0nQd7Gc081ByWGiiplD0iZS4WRn8nLbtu UFfMpiOwyrYQg== Message-ID: <640e1c7a-4356-70b7-d881-df13c8d72447@kernel.org> Date: Thu, 5 Oct 2023 07:43:01 +0900 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 Subject: Re: [PATCH 4/4] ata: pata_parport: fit3: implement IDE command set registers Content-Language: en-US To: Ondrej Zary , Sudip Mukherjee Cc: Christoph Hellwig , Sergey Shtylyov , Tim Waugh , linux-parport@lists.infradead.org, linux-ide@vger.kernel.org, linux-kernel@vger.kernel.org References: <20231004185235.27417-1-linux@zary.sk> <20231004185235.27417-5-linux@zary.sk> From: Damien Le Moal Organization: Western Digital Research In-Reply-To: <20231004185235.27417-5-linux@zary.sk> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/5/23 03:52, Ondrej Zary wrote: > 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 > --- > drivers/ata/pata_parport/fit3.c | 16 ++++------------ > 1 file changed, 4 insertions(+), 12 deletions(-) > > diff --git a/drivers/ata/pata_parport/fit3.c b/drivers/ata/pata_parport/fit3.c > index bad7aa920cdc..86b39966755b 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 > @@ -35,10 +30,11 @@ > * cont = 1 - access the IDE command set > */ > > +static int cont_map[] = { 0x00, 0x08 }; > + > static void fit3_write_regr(struct pi_adapter *pi, int cont, int regr, int val) > { > - if (cont == 1) > - return; > + regr += cont_map[cont]; It is a little silly to have that cont_map array for this only... Why not simply "regr += cont << 3;" ? Sergey suggested that already I think. > > switch (pi->mode) { > case 0: > @@ -59,11 +55,7 @@ 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_map[cont]; > > switch (pi->mode) { > case 0: -- Damien Le Moal Western Digital Research