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 8C840EB64D9 for ; Mon, 10 Jul 2023 17:00:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230427AbjGJRAi (ORCPT ); Mon, 10 Jul 2023 13:00:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58618 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230113AbjGJRAf (ORCPT ); Mon, 10 Jul 2023 13:00:35 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 39A64D7; Mon, 10 Jul 2023 10:00:34 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id CBB9961063; Mon, 10 Jul 2023 17:00:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C9BEBC433C7; Mon, 10 Jul 2023 17:00:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1689008433; bh=olt/eE72Fe/WemTa8hX4qWzKexWxP3mHF33PZCU7i9I=; h=Subject:From:To:Date:In-Reply-To:References:From; b=myb7n+TDAMq+1aoTOqi2avGRFtbWQ0Xwo2eeJDzqim66ZnirfK67FwKBqW7Q8PBVR Y1KmAjtfvL+d1MlUYOD54vWBG7KNDuLtIPYhbPCtyVyPXHrjbe5wWQRjWNn4qVlN8f F/t/3gimacqsqfL46+vXf/Mhkc2iIe7oCYXO+mTc4d2sc3kaKiWnAOE8WIzHrlNuFY XtwZgvJR+I2qXtk1CCIogxqOy/YWRfvb1g5PSNR4RCCjHWKlBtMR3xOu+Ddnw1g7BF jTrqA+h1kxzLg7n0lPjAJVu91ykBZHxdOHZBc5gH+QgQLzmjHa+fhpoCN7CE2ZI32s T7WnBRuNQFqhQ== Message-ID: Subject: Re: [PATCH v3 4/4] tpm_tis: Resend command to recover from data transfer errors From: Jarkko Sakkinen To: Alexander Steffen , linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org Date: Mon, 10 Jul 2023 20:00:29 +0300 In-Reply-To: <20230613180259.3525-5-Alexander.Steffen@infineon.com> References: <20230613180259.3525-1-Alexander.Steffen@infineon.com> <20230613180259.3525-5-Alexander.Steffen@infineon.com> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.48.1-0ubuntu1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2023-06-13 at 20:02 +0200, Alexander Steffen wrote: > Similar to the transmission of TPM responses, also the transmission of TP= M > commands may become corrupted. Instead of aborting when detecting such > issues, try resending the command again. >=20 > Signed-off-by: Alexander Steffen > --- > drivers/char/tpm/tpm_tis_core.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) >=20 > diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_c= ore.c > index a6d1396413a7..7b13ad4bd6dd 100644 > --- a/drivers/char/tpm/tpm_tis_core.c > +++ b/drivers/char/tpm/tpm_tis_core.c > @@ -532,10 +532,17 @@ static int tpm_tis_send_main(struct tpm_chip *chip,= const u8 *buf, size_t len) > int rc; > u32 ordinal; > unsigned long dur; > + unsigned int try; > =20 > - rc =3D tpm_tis_send_data(chip, buf, len); > - if (rc < 0) > - return rc; > + for (try =3D 0; try < TPM_RETRY; try++) { > + rc =3D tpm_tis_send_data(chip, buf, len); > + if (rc >=3D 0) > + /* Data transfer done successfully */ > + break; > + else if (rc !=3D -EIO) > + /* Data transfer failed, not recoverable */ > + return rc; > + } > =20 > /* go and do it */ > rc =3D tpm_tis_write8(priv, TPM_STS(priv->locality), TPM_STS_GO); Reviewed-by: Jarkko Sakkinen BR, Jarkko