From patchwork Tue Nov 14 08:55:25 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joshua Yeong X-Patchwork-Id: 13454968 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E5398C4332F for ; Tue, 14 Nov 2023 08:56:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:CC:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=hZ7CO37zbyxE6LcAQSOUpVqa61oHt13KqZZfK7sWO/g=; b=cABCJyKgh/zaRh MojiqVK2FZztxMn591KetoikZGYuyP4FSX5mqTyCWCzR6ZWvJUopY36xCDPjMfvHgoi4r7MJ8XdY/ UbAI64ypbZ56K2GbGUvgJrEG5nhdOMDDLdExhIuihZ9bGDuh3Q6VfH9EwINmNI58QSkj2PdqYMQ2p 7BuB0LC+fFAFbC+hoStlIcoCBV15WRZZ6a6s/UA5dkkrSWFY2yUjCK5Im0mwb4CSSt2QTCXRTum9m C0NYlQ86vsplOnGMdpD63kuoD6isCnB1DZERLdlUGwH13fxUR38fgWmpxSRDALlJpKSBAtoLnCZZQ Ba6k1iiEKhsVB56QVlFA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r2pDp-00FR6W-2D; Tue, 14 Nov 2023 08:56:37 +0000 Received: from fd01.gateway.ufhost.com ([61.152.239.71]) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r2pDm-00FR4o-2c for linux-i3c@lists.infradead.org; Tue, 14 Nov 2023 08:56:36 +0000 Received: from EXMBX166.cuchost.com (unknown [175.102.18.54]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "EXMBX166", Issuer "EXMBX166" (not verified)) by fd01.gateway.ufhost.com (Postfix) with ESMTP id D2F628143; Tue, 14 Nov 2023 16:56:14 +0800 (CST) Received: from EXMBX066.cuchost.com (172.16.7.66) by EXMBX166.cuchost.com (172.16.6.76) with Microsoft SMTP Server (TLS) id 15.0.1497.42; Tue, 14 Nov 2023 16:56:14 +0800 Received: from localhost.localdomain (161.142.156.149) by EXMBX066.cuchost.com (172.16.6.66) with Microsoft SMTP Server (TLS) id 15.0.1497.42; Tue, 14 Nov 2023 16:56:11 +0800 From: Joshua Yeong To: , CC: , , "Joshua Yeong" Subject: [PATCH v3 1/1] i3c: Add fallback method for GETMXDS CCC Date: Tue, 14 Nov 2023 16:55:25 +0800 Message-ID: <20231114085525.6271-2-joshua.yeong@starfivetech.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20231114085525.6271-1-joshua.yeong@starfivetech.com> References: <20231114085525.6271-1-joshua.yeong@starfivetech.com> MIME-Version: 1.0 X-Originating-IP: [161.142.156.149] X-ClientProxiedBy: EXCAS062.cuchost.com (172.16.6.22) To EXMBX066.cuchost.com (172.16.6.66) X-YovoleRuleAgent: yovoleflag X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231114_005634_998955_7DFAED26 X-CRM114-Status: GOOD ( 14.28 ) X-BeenThere: linux-i3c@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-i3c" Errors-To: linux-i3c-bounces+linux-i3c=archiver.kernel.org@lists.infradead.org Some I3C hardware will report error when an incorrect length is received from device. GETMXDS CCC are available in 2 formats: without turnaround time (format 1) and with turnaround time (format 2). There is no mechanics to determine which format is supported by device. So in case sending GETMXDS CCC format 2 resulted in a failure, try sending GETMXDS CCC format 1 instead. Signed-off-by: Joshua Yeong Reviewed-by: Miquel Raynal --- drivers/i3c/master.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c index 95caa162706f..718b643cb54d 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -1130,8 +1130,16 @@ static int i3c_master_getmxds_locked(struct i3c_master_controller *master, i3c_ccc_cmd_init(&cmd, true, I3C_CCC_GETMXDS, &dest, 1); ret = i3c_master_send_ccc_cmd_locked(master, &cmd); - if (ret) - goto out; + if (ret) { + /* + * Retry when the device does not support max read turnaround + * while expecting shorter length from this CCC command. + */ + dest->payload.len -= 3; + ret = i3c_master_send_ccc_cmd_locked(master, &cmd); + if (ret) + goto out; + } if (dest.payload.len != 2 && dest.payload.len != 5) { ret = -EIO;