From patchwork Thu Apr 21 14:34:49 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tomi Valkeinen X-Patchwork-Id: 564671 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 71503C433FE for ; Thu, 21 Apr 2022 14:35:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1389418AbiDUOiF (ORCPT ); Thu, 21 Apr 2022 10:38:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44558 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1389505AbiDUOh6 (ORCPT ); Thu, 21 Apr 2022 10:37:58 -0400 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6DB1D2197 for ; Thu, 21 Apr 2022 07:35:08 -0700 (PDT) Received: from deskari.lan (91-156-85-209.elisa-laajakaista.fi [91.156.85.209]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 6F175492; Thu, 21 Apr 2022 16:35:03 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1650551704; bh=iWfMFpq2rZDj4cb4x7bR8yKDVCM80TcX5tkvI6XufXo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Nyagb0NQrGdIgyZ0PaLoGZJa1oKkONQ7uqjP2fEf5uMbIF8Ja/hGl3xR8/ddiOOp4 8h1EmuxJLv44E7un5q+FurdfEdi03ldua0Z+zZYLu8K/GtZHRGdr6OJhkvauuHLzpF Fe7JLEWAPpWw9esJxOV5K5V68Efjy3SZv1loi6Hc= From: Tomi Valkeinen To: linux-media@vger.kernel.org, sakari.ailus@linux.intel.com, Jacopo Mondi , Laurent Pinchart , niklas.soderlund+renesas@ragnatech.se, Mauro Carvalho Chehab , Hans Verkuil , Pratyush Yadav Cc: Tomi Valkeinen Subject: [PATCH 6/6] media: ti: cal: fix wdma irq for metadata Date: Thu, 21 Apr 2022 17:34:49 +0300 Message-Id: <20220421143449.552312-7-tomi.valkeinen@ideasonboard.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220421143449.552312-1-tomi.valkeinen@ideasonboard.com> References: <20220421143449.552312-1-tomi.valkeinen@ideasonboard.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org CAL HW interrupts are inherently racy. If we get both start and end interrupts, we don't know what has happened: did the DMA for a single frame start and end, or did one frame end and a new frame start? Usually for normal pixel frames we get the interrupts separately. If we do get both, we have to guess. The assumption in the code is that the active vertical area is larger than the blanking vertical area, and thus it is more likely that we get the end of the old frame and the start of a new frame. However, for embedded data, which is only a few lines high, we always get both interrupts. Here the assumption is that we get both for the same frame. Signed-off-by: Tomi Valkeinen --- drivers/media/platform/ti/cal/cal.c | 33 ++++++++++++++++++++++++----- 1 file changed, 28 insertions(+), 5 deletions(-) diff --git a/drivers/media/platform/ti/cal/cal.c b/drivers/media/platform/ti/cal/cal.c index e4355f266c58..12de9171e353 100644 --- a/drivers/media/platform/ti/cal/cal.c +++ b/drivers/media/platform/ti/cal/cal.c @@ -670,11 +670,34 @@ static inline void cal_irq_wdma_end(struct cal_ctx *ctx) static void cal_irq_handle_wdma(struct cal_ctx *ctx, bool start, bool end) { - if (end) - cal_irq_wdma_end(ctx); - - if (start) - cal_irq_wdma_start(ctx); + /* + * CAL HW interrupts are inherently racy. If we get both start and end + * interrupts, we don't know what has happened: did the DMA for a single + * frame start and end, or did one frame end and a new frame start? + * + * Usually for normal pixel frames we get the interrupts separately. If + * we do get both, we have to guess. The assumption in the code below is + * that the active vertical area is larger than the blanking vertical + * area, and thus it is more likely that we get the end of the old frame + * and the start of a new frame. + * + * However, for embedded data, which is only a few lines high, we always + * get both interrupts. Here the assumption is that we get both for the + * same frame. + */ + if (ctx->v_fmt.fmt.pix.height < 10) { + if (start) + cal_irq_wdma_start(ctx); + + if (end) + cal_irq_wdma_end(ctx); + } else { + if (end) + cal_irq_wdma_end(ctx); + + if (start) + cal_irq_wdma_start(ctx); + } } static irqreturn_t cal_irq(int irq_cal, void *data)