From patchwork Fri Mar 13 08:26:39 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomi Valkeinen X-Patchwork-Id: 11436235 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0D7AE92A for ; Fri, 13 Mar 2020 08:26:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D843D2073E for ; Fri, 13 Mar 2020 08:26:50 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="B+oGXnAU" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726436AbgCMI0u (ORCPT ); Fri, 13 Mar 2020 04:26:50 -0400 Received: from lelv0142.ext.ti.com ([198.47.23.249]:57590 "EHLO lelv0142.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726310AbgCMI0t (ORCPT ); Fri, 13 Mar 2020 04:26:49 -0400 Received: from fllv0034.itg.ti.com ([10.64.40.246]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id 02D8Qjbx077264; Fri, 13 Mar 2020 03:26:45 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1584088006; bh=2bdXDCOVDjRjbQeEOa6u440gjSuQopkMK3OEOqfHEbw=; h=From:To:CC:Subject:Date; b=B+oGXnAUQocz0I6EYxrX3yADZptvLTyMoERZM1oPC9wo0MLHgRK9VY31ABk07kFAD 3uV4+OBojRXPcHmO7Lq3+bVU1dOyb1u9m2p3uVHMmeGFCn5ZAybg4Ay9QByfdONEIh pXOKHPYhz0k0JehN3CjUg8rcykBsDVBOvQjH/otQ= Received: from DLEE104.ent.ti.com (dlee104.ent.ti.com [157.170.170.34]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 02D8Qj0X059369 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Fri, 13 Mar 2020 03:26:45 -0500 Received: from DLEE114.ent.ti.com (157.170.170.25) by DLEE104.ent.ti.com (157.170.170.34) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3; Fri, 13 Mar 2020 03:26:45 -0500 Received: from localhost.localdomain (10.64.41.19) by DLEE114.ent.ti.com (157.170.170.25) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1847.3 via Frontend Transport; Fri, 13 Mar 2020 03:26:45 -0500 Received: from deskari.lan (ileax41-snat.itg.ti.com [10.172.224.153]) by localhost.localdomain (8.15.2/8.15.2) with ESMTP id 02D8Qhdf113654; Fri, 13 Mar 2020 03:26:44 -0500 From: Tomi Valkeinen To: Mauro Carvalho Chehab , , Benoit Parrot CC: Laurent Pinchart , Tomi Valkeinen , Subject: [PATCH] media: ti-vpe: cal: fix DMA memory corruption Date: Fri, 13 Mar 2020 10:26:39 +0200 Message-ID: <20200313082639.7743-1-tomi.valkeinen@ti.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org When the CAL driver stops streaming, it will shut everything down without waiting for the current frame to finish. This leaves the CAL DMA in a slightly undefined state, and when CAL DMA is enabled when the stream is started the next time, the old DMA transfer will continue. It is not clear if the old DMA transfer continues with the exact settings of the original transfer, or is it a mix of old and new settings, but in any case the end result is memory corruption as the destination memory address is no longer valid. I could not find any way to ensure that any old DMA transfer would be discarded, except perhaps full CAL reset. But we cannot do a full reset when one port is getting enabled, as that would reset both ports. This patch tries to make sure that the DMA transfer is finished properly when the stream is being stopped. I say "tries", as, as mentioned above, I don't see a way to force the DMA transfer to finish. I believe this fixes the corruptions for normal cases, but if for some reason the DMA of the final frame would stall a lot, resulting in timeout in the code waiting for the DMA to finish, we'll again end up with unfinished DMA transfer. However, I don't know what could cause such a timeout. Signed-off-by: Tomi Valkeinen Cc: stable@vger.kernel.org --- drivers/media/platform/ti-vpe/cal.c | 32 +++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/drivers/media/platform/ti-vpe/cal.c b/drivers/media/platform/ti-vpe/cal.c index be54806180a5..b857cab120ad 100644 --- a/drivers/media/platform/ti-vpe/cal.c +++ b/drivers/media/platform/ti-vpe/cal.c @@ -414,6 +414,8 @@ struct cal_ctx { struct cal_buffer *cur_frm; /* Pointer pointing to next v4l2_buffer */ struct cal_buffer *next_frm; + + bool dma_act; }; static const struct cal_fmt *find_format_by_pix(struct cal_ctx *ctx, @@ -944,6 +946,7 @@ static void csi2_lane_config(struct cal_ctx *ctx) static void csi2_ppi_enable(struct cal_ctx *ctx) { + reg_write(ctx->dev, CAL_CSI2_PPI_CTRL(ctx->csi2_port), BIT(3)); reg_write_field(ctx->dev, CAL_CSI2_PPI_CTRL(ctx->csi2_port), CAL_GEN_ENABLE, CAL_CSI2_PPI_CTRL_IF_EN_MASK); } @@ -1206,15 +1209,25 @@ static irqreturn_t cal_irq(int irq_cal, void *data) if (isportirqset(irqst2, 1)) { ctx = dev->ctx[0]; + spin_lock(&ctx->slock); + ctx->dma_act = false; + if (ctx->cur_frm != ctx->next_frm) cal_process_buffer_complete(ctx); + + spin_unlock(&ctx->slock); } if (isportirqset(irqst2, 2)) { ctx = dev->ctx[1]; + spin_lock(&ctx->slock); + ctx->dma_act = false; + if (ctx->cur_frm != ctx->next_frm) cal_process_buffer_complete(ctx); + + spin_unlock(&ctx->slock); } } @@ -1230,6 +1243,7 @@ static irqreturn_t cal_irq(int irq_cal, void *data) dma_q = &ctx->vidq; spin_lock(&ctx->slock); + ctx->dma_act = true; if (!list_empty(&dma_q->active) && ctx->cur_frm == ctx->next_frm) cal_schedule_next_buffer(ctx); @@ -1241,6 +1255,7 @@ static irqreturn_t cal_irq(int irq_cal, void *data) dma_q = &ctx->vidq; spin_lock(&ctx->slock); + ctx->dma_act = true; if (!list_empty(&dma_q->active) && ctx->cur_frm == ctx->next_frm) cal_schedule_next_buffer(ctx); @@ -1713,10 +1728,27 @@ static void cal_stop_streaming(struct vb2_queue *vq) struct cal_ctx *ctx = vb2_get_drv_priv(vq); struct cal_dmaqueue *dma_q = &ctx->vidq; struct cal_buffer *buf, *tmp; + unsigned long timeout; unsigned long flags; int ret; + bool dma_act; csi2_ppi_disable(ctx); + + /* wait for stream and dma to finish */ + dma_act = true; + timeout = jiffies + msecs_to_jiffies(500); + while (dma_act && time_before(jiffies, timeout)) { + msleep(50); + + spin_lock_irqsave(&ctx->slock, flags); + dma_act = ctx->dma_act; + spin_unlock_irqrestore(&ctx->slock, flags); + } + + if (dma_act) + ctx_err(ctx, "failed to disable dma cleanly\n"); + disable_irqs(ctx); csi2_phy_deinit(ctx);