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 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 2211BF94CA1 for ; Tue, 21 Apr 2026 17:55:18 +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=Mvb9I0jNazoI8i4aVukltudWyA5ZREWmsfzd5pVShZM=; b=S9DY4Z2SAp8+19 XdV/vXbQO7AvI1UuLFXLTc2vZ5AcB9isEqbPPLjVC49VLJzSnvCi/QzP4X3yhUi2wtFz+SRYuolPK cjzRatqJIR2wofIIAo3ud0TFApvQ4kVhn8VMuQWKFQo4qMIjEYKYkYmFl/oC2TVLpuV4gH68pDhag FKhcZRpLDG/ASrh4YHuiNg1mdtAuMKU8WMr7Rs0gnR9faVguBjXj0HQo4K9haI/PNPetLtpCPQ2nG PF+BJr2HXpG5g1q5k/aYrEPJhUGfhwaM/Ve7fjeX6SvcefQxWWsW0Whk8QSAsKbSBnLSzTnlx16JM LeaXz9HToxrBBpkNKHug==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1wFFJd-00000008zjU-3XRN; Tue, 21 Apr 2026 17:55:17 +0000 Received: from mgamail.intel.com ([198.175.65.19]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1wFFJY-00000008zV1-49mP for linux-i3c@lists.infradead.org; Tue, 21 Apr 2026 17:55:14 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1776794113; x=1808330113; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=NyxPCoYT9Rl8/SExmUHfy6bSoYpnDgLx2B/OTHDnyhE=; b=mZWrfl6iKpN+q1GnEv/jnuOQrD3Q/7ZTQrAI8xQEYInGiMPZAB9PU3Ff /uP1p3UB34cCO/jVJv5HKo4Ipga2DbT5snAi4h6kTG246WedHsOBst/gm ds+f4ej8iU6HQaGvvbN9wAeyKQf48E3ChhTytXeDva/3cTdlECtoN/fB+ rCTp4gjN3gDvQ2cTYWIuvIKlFXYGyz6riXqwqVoCnJVWg/aoQ6CfkP1t3 MspFvdbjv60YvadeKPmxfTKcdLmoB6ZRqOrzR02fq97GoYRF4PGzlUYji vNQ+cmMGd9fepKKveyrk10m8Fs9I0RaZBFNnkO7fkdNf3Xz/IBs6mAcYD g==; X-CSE-ConnectionGUID: v2QNLpVFTwGUpxuVvLp2vA== X-CSE-MsgGUID: 71fapKjsRf2ZELutLMvvNw== X-IronPort-AV: E=McAfee;i="6800,10657,11763"; a="77651423" X-IronPort-AV: E=Sophos;i="6.23,192,1770624000"; d="scan'208";a="77651423" Received: from fmviesa006.fm.intel.com ([10.60.135.146]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2026 10:55:13 -0700 X-CSE-ConnectionGUID: noQ4Wp5xQleqd1+7zJNmvw== X-CSE-MsgGUID: CZUq/NcQTV6e7XPHd27+BA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.23,192,1770624000"; d="scan'208";a="227495079" Received: from hrotuna-mobl2.ger.corp.intel.com (HELO ahunter6-desk) ([10.245.244.242]) by fmviesa006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 21 Apr 2026 10:55:11 -0700 From: Adrian Hunter To: alexandre.belloni@bootlin.com Cc: Frank.Li@nxp.com, linux-i3c@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH V2 14/16] i3c: mipi-i3c-hci: Base timeouts on actual transfer start time Date: Tue, 21 Apr 2026 20:54:33 +0300 Message-ID: <20260421175435.122094-15-adrian.hunter@intel.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260421175435.122094-1-adrian.hunter@intel.com> References: <20260421175435.122094-1-adrian.hunter@intel.com> MIME-Version: 1.0 Organization: Intel Finland Oy, Registered Address: c/o Alberga Business Park, 6 krs, Bertel Jungin Aukio 5, 02600 Espoo, Business Identity Code: 0357606 - 4, Domiciled in Helsinki X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260421_105513_085952_1EAF2D96 X-CRM114-Status: GOOD ( 20.21 ) 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: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-i3c" Errors-To: linux-i3c-bounces+linux-i3c=archiver.kernel.org@lists.infradead.org Transfer timeouts are currently measured from the point where a transfer list is queued to the controller. This can cause transfers to time out before they have actually started, if earlier queued transfers consume the timeout interval. Fix this by recording when a transfer reaches the head of the queue and adjusting the timeout calculation to start from that point. The existing low-overhead completion-based timeout mechanism is preserved, but care is taken to ensure the transfer start time is consistently recorded for both PIO and DMA paths. This prevents premature timeouts while retaining efficient timeout handling. Signed-off-by: Adrian Hunter --- Changes in V2: Do not flag the next transfer as started when there is an error which halts the controller Instead flag it started at the end of hci_dma_dequeue_xfer() Use hci_start_xfer() in pio.c drivers/i3c/master/mipi-i3c-hci/core.c | 19 ++++++++++++++++++- drivers/i3c/master/mipi-i3c-hci/dma.c | 19 ++++++++++++++++++- drivers/i3c/master/mipi-i3c-hci/hci.h | 11 +++++++++++ drivers/i3c/master/mipi-i3c-hci/pio.c | 1 + 4 files changed, 48 insertions(+), 2 deletions(-) diff --git a/drivers/i3c/master/mipi-i3c-hci/core.c b/drivers/i3c/master/mipi-i3c-hci/core.c index 69dcf5dad3a5..2866d599612a 100644 --- a/drivers/i3c/master/mipi-i3c-hci/core.c +++ b/drivers/i3c/master/mipi-i3c-hci/core.c @@ -275,13 +275,30 @@ int i3c_hci_process_xfer(struct i3c_hci *hci, struct hci_xfer *xfer, int n) { struct completion *done = xfer[n - 1].completion; unsigned long timeout = xfer[n - 1].timeout; + unsigned long remaining_timeout = timeout; + long time_taken; + bool started; int ret; + xfer[0].started = false; + ret = hci->io->queue_xfer(hci, xfer, n); if (ret) return ret; - if (!wait_for_completion_timeout(done, timeout)) { + while (!wait_for_completion_timeout(done, remaining_timeout)) { + scoped_guard(spinlock_irqsave, &hci->lock) { + started = xfer[0].started; + time_taken = jiffies - xfer[0].start_time; + } + /* Keep waiting if xfer has not started */ + if (!started) + continue; + /* Recalculate timeout based on actual start time */ + if (time_taken < timeout) { + remaining_timeout = timeout - time_taken; + continue; + } if (hci->io->dequeue_xfer(hci, xfer, n)) { dev_err(&hci->master.dev, "%s: timeout error\n", __func__); return -ETIMEDOUT; diff --git a/drivers/i3c/master/mipi-i3c-hci/dma.c b/drivers/i3c/master/mipi-i3c-hci/dma.c index dfc91de66ba5..e169f20608a0 100644 --- a/drivers/i3c/master/mipi-i3c-hci/dma.c +++ b/drivers/i3c/master/mipi-i3c-hci/dma.c @@ -543,6 +543,9 @@ static int hci_dma_queue_xfer(struct i3c_hci *hci, enqueue_ptr = (enqueue_ptr + 1) % rh->xfer_entries; } + if (rh->xfer_space == rh->xfer_entries) + hci_start_xfer(xfer_list); + rh->xfer_space -= n; op1_val &= ~RING_OP1_CR_ENQ_PTR; @@ -558,6 +561,7 @@ static void hci_dma_xfer_done(struct i3c_hci *hci, struct hci_rh_data *rh) u32 op1_val, op2_val, resp, *ring_resp; unsigned int tid, done_ptr = rh->done_ptr; unsigned int done_cnt = 0; + bool start_next = false; struct hci_xfer *xfer; for (;;) { @@ -588,8 +592,14 @@ static void hci_dma_xfer_done(struct i3c_hci *hci, struct hci_rh_data *rh) xfer->response = resp; if (xfer == xfer->final_xfer || RESP_STATUS(resp)) complete(xfer->final_xfer->completion); - if (RESP_STATUS(resp)) + else + hci_start_xfer(xfer); + if (RESP_STATUS(resp)) { hci->enqueue_blocked = true; + start_next = false; + } else { + start_next = true; + } } done_ptr = (done_ptr + 1) % rh->xfer_entries; @@ -598,6 +608,10 @@ static void hci_dma_xfer_done(struct i3c_hci *hci, struct hci_rh_data *rh) } rh->xfer_space += done_cnt; + if (start_next && rh->xfer_space < rh->xfer_entries) { + xfer = rh->src_xfers[done_ptr]; + hci_start_xfer(xfer); + } op1_val = rh_reg_read(RING_OPERATION1); op1_val &= ~RING_OP1_CR_SW_DEQ_PTR; op1_val |= FIELD_PREP(RING_OP1_CR_SW_DEQ_PTR, done_ptr); @@ -816,6 +830,9 @@ static bool hci_dma_dequeue_xfer(struct i3c_hci *hci, hci_dma_unblock_enqueue(hci); + if (rh->xfer_space < rh->xfer_entries) + hci_start_xfer(rh->src_xfers[rh->done_ptr]); + spin_unlock_irq(&hci->lock); wait_for_completion_timeout(&rh->op_done, HZ); diff --git a/drivers/i3c/master/mipi-i3c-hci/hci.h b/drivers/i3c/master/mipi-i3c-hci/hci.h index 4bf2c66c97b4..243d7a67f6f6 100644 --- a/drivers/i3c/master/mipi-i3c-hci/hci.h +++ b/drivers/i3c/master/mipi-i3c-hci/hci.h @@ -11,6 +11,7 @@ #define HCI_H #include +#include /* 32-bit word aware bit and mask macros */ #define W0_MASK(h, l) GENMASK((h) - 0, (l) - 0) @@ -88,11 +89,13 @@ struct hci_xfer { u32 cmd_desc[4]; u32 response; bool rnw; + bool started; void *data; unsigned int data_len; unsigned int cmd_tid; struct completion *completion; unsigned long timeout; + unsigned long start_time; union { struct { /* PIO specific */ @@ -123,6 +126,14 @@ static inline void hci_free_xfer(struct hci_xfer *xfer, unsigned int n) kfree(xfer); } +static inline void hci_start_xfer(struct hci_xfer *xfer) +{ + if (!xfer->started) { + xfer->started = true; + xfer->start_time = jiffies; + } +} + /* This abstracts PIO vs DMA operations */ struct hci_io_ops { bool (*irq_handler)(struct i3c_hci *hci); diff --git a/drivers/i3c/master/mipi-i3c-hci/pio.c b/drivers/i3c/master/mipi-i3c-hci/pio.c index 8f48a81e65ab..6b8cc5f2b4d2 100644 --- a/drivers/i3c/master/mipi-i3c-hci/pio.c +++ b/drivers/i3c/master/mipi-i3c-hci/pio.c @@ -605,6 +605,7 @@ static bool hci_pio_process_cmd(struct i3c_hci *hci, struct hci_pio_data *pio) * Finally send the command. */ hci_pio_write_cmd(hci, pio->curr_xfer); + hci_start_xfer(pio->curr_xfer); /* * And move on. */ -- 2.51.0 -- linux-i3c mailing list linux-i3c@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-i3c