From patchwork Fri Mar 8 21:00:32 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sean Anderson X-Patchwork-Id: 13587279 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 7A96AC54E41 for ; Fri, 8 Mar 2024 21:01:07 +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=wWaPMeOSz8WzgRQy6XutvJtHsCCSRxTiX1JOMmHxioU=; b=N/B/JZcn57FzTr gMNAsD4pBghBea7RtmmZtiT/gtfyoKP5LjmNi6ETExNDfFOaF4sJbCzt2707CDwRHgtScqDsajuDd 2iBvYqv3F7M+ZnE83FKk6037qESn+e/cfmzH5GOUf+Z+4sluJiAxPBOXAk+Hd29DGSN0HHS98KI9q rrhlpht1F8TAkVRdiUZsUR/TtSb+05UwwTK6rE6xLhDLYhqDr4p0oz4iN3PU+8rQI0OevtQrw3hhB MpdR6Eb3JP3hNzG4ywLt49BNCuFv0j48nmXhiw5ZEkoOxww3zNK7haFF8pZCiY9mm7geAwvwHmUtu +5NeMRAGVXwgt0NG9NXg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rihKk-0000000BIXu-3lMT; Fri, 08 Mar 2024 21:00:50 +0000 Received: from out-183.mta1.migadu.com ([95.215.58.183]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rihKe-0000000BIVG-3B83 for linux-arm-kernel@lists.infradead.org; Fri, 08 Mar 2024 21:00:46 +0000 X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1709931641; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=lZZlTtmAYhSYsdD4AVhRHcVqqgxhut5qRVX6YFKjyog=; b=Pj/741ClmbkHAA/5Oz1i/mchI2TGZrw1Td4707+0+Zsp1iI71JeFqLks53iPOjJ8EmYKVw DlEsCU2OcyxeHjH/gGRef5x4osZLDP77JFi1g3IkeijG3vWzKgynDPuXx8gMk+tJ4m0Ifa IB2YKrZ8SP6TXEcjqygxl3Io9LdNx7s= From: Sean Anderson To: Laurent Pinchart , Vinod Koul , dmaengine@vger.kernel.org Cc: Michal Simek , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Sean Anderson , Hyun Kwon , Tejas Upadhyay Subject: [PATCH 1/3] dma: xilinx_dpdma: Fix locking Date: Fri, 8 Mar 2024 16:00:32 -0500 Message-Id: <20240308210034.3634938-2-sean.anderson@linux.dev> In-Reply-To: <20240308210034.3634938-1-sean.anderson@linux.dev> References: <20240308210034.3634938-1-sean.anderson@linux.dev> MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240308_130044_973144_7DC60A34 X-CRM114-Status: GOOD ( 11.63 ) X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org There are several places where either chan->lock or chan->vchan.lock was not held. Add appropriate locking. This fixes lockdep warnings like [ 31.077578] ------------[ cut here ]------------ [ 31.077831] WARNING: CPU: 2 PID: 40 at drivers/dma/xilinx/xilinx_dpdma.c:834 xilinx_dpdma_chan_queue_transfer+0x274/0x5e0 [ 31.077953] Modules linked in: [ 31.078019] CPU: 2 PID: 40 Comm: kworker/u12:1 Not tainted 6.6.20+ #98 [ 31.078102] Hardware name: xlnx,zynqmp (DT) [ 31.078169] Workqueue: events_unbound deferred_probe_work_func [ 31.078272] pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 31.078377] pc : xilinx_dpdma_chan_queue_transfer+0x274/0x5e0 [ 31.078473] lr : xilinx_dpdma_chan_queue_transfer+0x270/0x5e0 [ 31.078550] sp : ffffffc083bb2e10 [ 31.078590] x29: ffffffc083bb2e10 x28: 0000000000000000 x27: ffffff880165a168 [ 31.078754] x26: ffffff880164e920 x25: ffffff880164eab8 x24: ffffff880164d480 [ 31.078920] x23: ffffff880165a148 x22: ffffff880164e988 x21: 0000000000000000 [ 31.079132] x20: ffffffc082aa3000 x19: ffffff880164e880 x18: 0000000000000000 [ 31.079295] x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 [ 31.079453] x14: 0000000000000000 x13: ffffff8802263dc0 x12: 0000000000000001 [ 31.079613] x11: 0001ffc083bb2e34 x10: 0001ff880164e98f x9 : 0001ffc082aa3def [ 31.079824] x8 : 0001ffc082aa3dec x7 : 0000000000000000 x6 : 0000000000000516 [ 31.079982] x5 : ffffffc7f8d43000 x4 : ffffff88003c9c40 x3 : ffffffffffffffff [ 31.080147] x2 : ffffffc7f8d43000 x1 : 00000000000000c0 x0 : 0000000000000000 [ 31.080307] Call trace: [ 31.080340] xilinx_dpdma_chan_queue_transfer+0x274/0x5e0 [ 31.080518] xilinx_dpdma_issue_pending+0x11c/0x120 [ 31.080595] zynqmp_disp_layer_update+0x180/0x3ac [ 31.080712] zynqmp_dpsub_plane_atomic_update+0x11c/0x21c [ 31.080825] drm_atomic_helper_commit_planes+0x20c/0x684 [ 31.080951] drm_atomic_helper_commit_tail+0x5c/0xb0 [ 31.081139] commit_tail+0x234/0x294 [ 31.081246] drm_atomic_helper_commit+0x1f8/0x210 [ 31.081363] drm_atomic_commit+0x100/0x140 [ 31.081477] drm_client_modeset_commit_atomic+0x318/0x384 [ 31.081634] drm_client_modeset_commit_locked+0x8c/0x24c [ 31.081725] drm_client_modeset_commit+0x34/0x5c [ 31.081812] __drm_fb_helper_restore_fbdev_mode_unlocked+0x104/0x168 [ 31.081899] drm_fb_helper_set_par+0x50/0x70 [ 31.081971] fbcon_init+0x538/0xc48 [ 31.082047] visual_init+0x16c/0x23c [ 31.082207] do_bind_con_driver.isra.0+0x2d0/0x634 [ 31.082320] do_take_over_console+0x24c/0x33c [ 31.082429] do_fbcon_takeover+0xbc/0x1b0 [ 31.082503] fbcon_fb_registered+0x2d0/0x34c [ 31.082663] register_framebuffer+0x27c/0x38c [ 31.082767] __drm_fb_helper_initial_config_and_unlock+0x5c0/0x91c [ 31.082939] drm_fb_helper_initial_config+0x50/0x74 [ 31.083012] drm_fbdev_dma_client_hotplug+0xb8/0x108 [ 31.083115] drm_client_register+0xa0/0xf4 [ 31.083195] drm_fbdev_dma_setup+0xb0/0x1cc [ 31.083293] zynqmp_dpsub_drm_init+0x45c/0x4e0 [ 31.083431] zynqmp_dpsub_probe+0x444/0x5e0 [ 31.083616] platform_probe+0x8c/0x13c [ 31.083713] really_probe+0x258/0x59c [ 31.083793] __driver_probe_device+0xc4/0x224 [ 31.083878] driver_probe_device+0x70/0x1c0 [ 31.083961] __device_attach_driver+0x108/0x1e0 [ 31.084052] bus_for_each_drv+0x9c/0x100 [ 31.084125] __device_attach+0x100/0x298 [ 31.084207] device_initial_probe+0x14/0x20 [ 31.084292] bus_probe_device+0xd8/0xdc [ 31.084368] deferred_probe_work_func+0x11c/0x180 [ 31.084451] process_one_work+0x3ac/0x988 [ 31.084643] worker_thread+0x398/0x694 [ 31.084752] kthread+0x1bc/0x1c0 [ 31.084848] ret_from_fork+0x10/0x20 [ 31.084932] irq event stamp: 64549 [ 31.084970] hardirqs last enabled at (64548): [] _raw_spin_unlock_irqrestore+0x80/0x90 [ 31.085157] hardirqs last disabled at (64549): [] _raw_spin_lock_irqsave+0xc0/0xdc [ 31.085277] softirqs last enabled at (64503): [] __do_softirq+0x47c/0x500 [ 31.085390] softirqs last disabled at (64498): [] ____do_softirq+0x10/0x1c [ 31.085501] ---[ end trace 0000000000000000 ]--- Fixes: 7cbb0c63de3f ("dmaengine: xilinx: dpdma: Add the Xilinx DisplayPort DMA engine driver") Signed-off-by: Sean Anderson Reviewed-by: Tomi Valkeinen --- drivers/dma/xilinx/xilinx_dpdma.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/dma/xilinx/xilinx_dpdma.c b/drivers/dma/xilinx/xilinx_dpdma.c index b82815e64d24..eb0637d90342 100644 --- a/drivers/dma/xilinx/xilinx_dpdma.c +++ b/drivers/dma/xilinx/xilinx_dpdma.c @@ -214,7 +214,8 @@ struct xilinx_dpdma_tx_desc { * @running: true if the channel is running * @first_frame: flag for the first frame of stream * @video_group: flag if multi-channel operation is needed for video channels - * @lock: lock to access struct xilinx_dpdma_chan + * @lock: lock to access struct xilinx_dpdma_chan. Must be taken before + * @vchan.lock, if both are to be held. * @desc_pool: descriptor allocation pool * @err_task: error IRQ bottom half handler * @desc: References to descriptors being processed @@ -1097,12 +1098,14 @@ static void xilinx_dpdma_chan_vsync_irq(struct xilinx_dpdma_chan *chan) * Complete the active descriptor, if any, promote the pending * descriptor to active, and queue the next transfer, if any. */ + spin_lock(&chan->vchan.lock); if (chan->desc.active) vchan_cookie_complete(&chan->desc.active->vdesc); chan->desc.active = pending; chan->desc.pending = NULL; xilinx_dpdma_chan_queue_transfer(chan); + spin_unlock(&chan->vchan.lock); out: spin_unlock_irqrestore(&chan->lock, flags); @@ -1264,10 +1267,12 @@ static void xilinx_dpdma_issue_pending(struct dma_chan *dchan) struct xilinx_dpdma_chan *chan = to_xilinx_chan(dchan); unsigned long flags; - spin_lock_irqsave(&chan->vchan.lock, flags); + spin_lock_irqsave(&chan->lock, flags); + spin_lock(&chan->vchan.lock); if (vchan_issue_pending(&chan->vchan)) xilinx_dpdma_chan_queue_transfer(chan); - spin_unlock_irqrestore(&chan->vchan.lock, flags); + spin_unlock(&chan->vchan.lock); + spin_unlock_irqrestore(&chan->lock, flags); } static int xilinx_dpdma_config(struct dma_chan *dchan, @@ -1495,7 +1500,9 @@ static void xilinx_dpdma_chan_err_task(struct tasklet_struct *t) XILINX_DPDMA_EINTR_CHAN_ERR_MASK << chan->id); spin_lock_irqsave(&chan->lock, flags); + spin_lock(&chan->vchan.lock); xilinx_dpdma_chan_queue_transfer(chan); + spin_unlock(&chan->vchan.lock); spin_unlock_irqrestore(&chan->lock, flags); }