From nobody Fri Oct 3 11:22:53 2025 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [213.167.242.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 43DB62FA0FC; Tue, 2 Sep 2025 10:57:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.167.242.64 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756810657; cv=none; b=c5LsSgVHUGh2kXm7xpezWGqVug42D/gHww9Jj6ZEFoVJrbqHC8vPS7tDqx8bZVjmNTK6RQ72ZkCDIoUKLudBgh0U5MYMRLqph5QTyHh7waiLI6Hp0iiUhts4etaWV1oPWAP7uqW+JcZWnWTCN114NlNEYXnt3bBlL+u3vej4rBQ= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756810657; c=relaxed/simple; bh=yK29nMj0x/n6vyRa/wmf8inh11piNH7wp9tI8JUNnPA=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=gcdqvSuiQfk8GQfFoLeAC5iIJBM8LMtwMByigokzzW3rbyGsVovXYH8zLF64ASE+yaWaXJ4YlDDllOYm2drf7/sZkSUl8Dd3I7CuobHZTk6Bzu2itCAUA60p6KR1AGWJzNtEYacdcYqx8q2WXtdR/c0BJAh5JsgJV9mZRx7qea8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com; spf=pass smtp.mailfrom=ideasonboard.com; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b=p4uuKyOO; arc=none smtp.client-ip=213.167.242.64 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ideasonboard.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ideasonboard.com header.i=@ideasonboard.com header.b="p4uuKyOO" Received: from mail.ideasonboard.com (unknown [IPv6:2401:4900:1c69:480e:e039:1d0b:c5ff:a9e2]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id B51D5C72; Tue, 2 Sep 2025 12:56:25 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1756810586; bh=yK29nMj0x/n6vyRa/wmf8inh11piNH7wp9tI8JUNnPA=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=p4uuKyOO//Wk/8NkBzRzYjK6tSNrsoS0vxIUMVfcaDIDJPuduaENYNRlPYjOekYXs RMgbi6vtFf5qlBJrSEwRRsinuiC0C0gDzd9iS81b0toQuEdXZzRSugrOd5t2Ojbe4j FJC1/ROAug4mlAXNjQQRzqdmqhFxMka0sArMWyOI= From: Jai Luthra Date: Tue, 02 Sep 2025 16:26:51 +0530 Subject: [PATCH v2 3/3] media: ti: j721e-csi2rx: Support system suspend using pm_notifier Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250902-ti_csi_pm-v2-3-59a3be199940@ideasonboard.com> References: <20250902-ti_csi_pm-v2-0-59a3be199940@ideasonboard.com> In-Reply-To: <20250902-ti_csi_pm-v2-0-59a3be199940@ideasonboard.com> To: Mauro Carvalho Chehab , Maxime Ripard , Philipp Zabel , Sakari Ailus Cc: linux-media@vger.kernel.org, linux-kernel@vger.kernel.org, Laurent Pinchart , Tomi Valkeinen , Changhuang Liang , Devarsh Thakkar , Rishikesh Donadkar , Jai Luthra X-Mailer: b4 0.14.2 X-Developer-Signature: v=1; a=openpgp-sha256; l=6315; i=jai.luthra@ideasonboard.com; h=from:subject:message-id; bh=yK29nMj0x/n6vyRa/wmf8inh11piNH7wp9tI8JUNnPA=; b=owEBbQKS/ZANAwAKAUPekfkkmnFFAcsmYgBots2GcoiTbnZO5rpex82JVzhv5SwYs3r4gAHkn a9BaMNVHsmJAjMEAAEKAB0WIQRN4NgY5dV16NRar8VD3pH5JJpxRQUCaLbNhgAKCRBD3pH5JJpx RSiyD/9ppkQe4UMAIjUQiC3u8HIex6vMh+R7qkGtgXvafaGrReAk0shvkcGYeLh3j2xwh6dKOby xc2VQLKjdem/TtmaP0qJCKYyoDHVTZt78CEwPpU6ruemszLzbFyP4jg5FklUh3t+uUcfHzN5Q9a pVSymfM5PFahlHsBK+Ja7rXwta3RYbkX6fy8CxibZqoYwdGiXjY+jqcwWazlGOw7YmL4aWttzCV tmWGU1Ph4W0/qPkK8MehCMA+DjbAjG/wuTzsk1Z53j3WxZS4pPHbbmwNaybg6zx4nDMvQNAPPxp oMcaZ0R6rUer5lptl6BjShrw0fC+s8C3qUZIaXtvCf8wSTxd2WtAnLAiJMch/PF+ZFpOh9cuDWC SfgvhKrxzAjUnyzlT6QnoZB9Xvi6jA07Kaauz1CZjQDlf55GeuErLWneAsaO1xyxhuTJeF64t/+ eqx8XsYDyopcV+JmU0FkM6kzkuLjzGC872lo8qrNWIL4ZPstAIIEYbri8hMTD3hao+rLsvKi3Fo DvIvvy1zegf9GW50sJ7+EMbk2TnsdpvEZ/WH5vvdg1MioCB0uzDDL6wbcQVVi4FvhXQ1BeTtKYX WGqbAtfzUQof0E8lpvFgPx8uAUAAmLh9S0tuxoLwWLh81S3pqZlKiXMfhe6XM7TorLS6bkclioN 4wiNobxzueFulug== X-Developer-Key: i=jai.luthra@ideasonboard.com; a=openpgp; fpr=4DE0D818E5D575E8D45AAFC543DE91F9249A7145 As this device is the "orchestrator" for the rest of the media pipeline, we need to stop all on-going streams before system suspend and enable them back when the system wakes up from sleep. Using .suspend/.resume callbacks does not work, as the order of those callbacks amongst various devices in the camera pipeline like the sensor, FPD serdes, CSI bridge etc. is impossible to enforce, even with device links. For example, the Cadence CSI bridge is a child device of this device, thus we cannot create a device link with the CSI bridge as a provider and this device as consumer. This can lead to situations where all the dependencies for the bridge have not yet resumed when we request the subdev to start streaming again through the .resume callback defined in this device. Instead here we register a notifier callback with the PM framework which is triggered when the system is fully functional. At this point we can cleanly stop or start the streams, because we know all other devices and their dependencies are functional. A downside of this approach is that the userspace is also alive (not frozen yet, or just thawed), so the suspend notifier might complete before the userspace has completed all ioctls, like QBUF/DQBUF/STREAMON/STREAMOFF. Tested-by: Rishikesh Donadkar Reviewed-by: Rishikesh Donadkar Signed-off-by: Jai Luthra --- .../media/platform/ti/j721e-csi2rx/j721e-csi2rx.c | 128 +++++++++++++++++= ++++ 1 file changed, 128 insertions(+) diff --git a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c b/driver= s/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c index a5cd7885f26b2cda87e0c68833c2cc584061698e..49860916a29ebe89a300d372368= f11ce4a078b50 100644 --- a/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c +++ b/drivers/media/platform/ti/j721e-csi2rx/j721e-csi2rx.c @@ -131,6 +131,7 @@ struct ti_csi2rx_dev { struct v4l2_subdev *source; struct v4l2_subdev subdev; struct ti_csi2rx_ctx ctx[TI_CSI2RX_MAX_CTX]; + struct notifier_block pm_notifier; u8 pix_per_clk; /* Buffer to drain stale data from PSI-L endpoint */ struct { @@ -1582,6 +1583,124 @@ static int ti_csi2rx_runtime_resume(struct device *= dev) return 0; } =20 +static int ti_csi2rx_suspend(struct device *dev) +{ + struct ti_csi2rx_dev *csi =3D dev_get_drvdata(dev); + enum ti_csi2rx_dma_state state; + struct ti_csi2rx_ctx *ctx; + struct ti_csi2rx_dma *dma; + unsigned long flags =3D 0; + int i, ret =3D 0; + + /* If device was not in use we can simply suspend */ + if (pm_runtime_status_suspended(dev)) + return 0; + + /* + * If device is running, assert the pixel reset to cleanly stop any + * on-going streams before we suspend. + */ + writel(0, csi->shim + SHIM_CNTL); + + for (i =3D 0; i < csi->num_ctx; i++) { + ctx =3D &csi->ctx[i]; + dma =3D &ctx->dma; + + spin_lock_irqsave(&dma->lock, flags); + state =3D dma->state; + spin_unlock_irqrestore(&dma->lock, flags); + + if (state !=3D TI_CSI2RX_DMA_STOPPED) { + /* Disable source */ + ret =3D v4l2_subdev_disable_streams(&csi->subdev, + TI_CSI2RX_PAD_FIRST_SOURCE + ctx->idx, + BIT(0)); + if (ret) + dev_err(csi->dev, "Failed to stop subdev stream\n"); + } + + /* Stop any on-going streams */ + writel(0, csi->shim + SHIM_DMACNTX(ctx->idx)); + + /* Drain DMA */ + ti_csi2rx_drain_dma(ctx); + + /* Terminate DMA */ + ret =3D dmaengine_terminate_sync(ctx->dma.chan); + if (ret) + dev_err(csi->dev, "Failed to stop DMA\n"); + } + + return ret; +} + +static int ti_csi2rx_resume(struct device *dev) +{ + struct ti_csi2rx_dev *csi =3D dev_get_drvdata(dev); + struct ti_csi2rx_ctx *ctx; + struct ti_csi2rx_dma *dma; + struct ti_csi2rx_buffer *buf; + unsigned long flags =3D 0; + unsigned int reg; + int i, ret =3D 0; + + /* If device was not in use, we can simply wakeup */ + if (pm_runtime_status_suspended(dev)) + return 0; + + /* If device was in use before, restore all the running streams */ + reg =3D SHIM_CNTL_PIX_RST; + writel(reg, csi->shim + SHIM_CNTL); + + for (i =3D 0; i < csi->num_ctx; i++) { + ctx =3D &csi->ctx[i]; + dma =3D &ctx->dma; + spin_lock_irqsave(&dma->lock, flags); + if (dma->state !=3D TI_CSI2RX_DMA_STOPPED) { + /* Re-submit all previously submitted buffers to DMA */ + list_for_each_entry(buf, &ctx->dma.submitted, list) { + ti_csi2rx_start_dma(ctx, buf); + } + spin_unlock_irqrestore(&dma->lock, flags); + + /* Restore stream config */ + ti_csi2rx_setup_shim(ctx); + + ret =3D v4l2_subdev_enable_streams(&csi->subdev, + TI_CSI2RX_PAD_FIRST_SOURCE + ctx->idx, + BIT(0)); + if (ret) + dev_err(ctx->csi->dev, "Failed to start subdev\n"); + } else { + spin_unlock_irqrestore(&dma->lock, flags); + } + } + + return ret; +} + +static int ti_csi2rx_pm_notifier(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct ti_csi2rx_dev *csi =3D + container_of(nb, struct ti_csi2rx_dev, pm_notifier); + + switch (action) { + case PM_HIBERNATION_PREPARE: + case PM_SUSPEND_PREPARE: + case PM_RESTORE_PREPARE: + ti_csi2rx_suspend(csi->dev); + break; + case PM_POST_SUSPEND: + case PM_POST_HIBERNATION: + case PM_POST_RESTORE: + ti_csi2rx_resume(csi->dev); + break; + } + + return NOTIFY_DONE; +} + static const struct dev_pm_ops ti_csi2rx_pm_ops =3D { RUNTIME_PM_OPS(ti_csi2rx_runtime_suspend, ti_csi2rx_runtime_resume, NULL) @@ -1653,6 +1772,13 @@ static int ti_csi2rx_probe(struct platform_device *p= dev) goto err_notifier; } =20 + csi->pm_notifier.notifier_call =3D ti_csi2rx_pm_notifier; + ret =3D register_pm_notifier(&csi->pm_notifier); + if (ret) { + dev_err(csi->dev, "Failed to create PM notifier: %d\n", ret); + goto err_notifier; + } + pm_runtime_set_active(csi->dev); pm_runtime_enable(csi->dev); pm_request_idle(csi->dev); @@ -1683,6 +1809,8 @@ static void ti_csi2rx_remove(struct platform_device *= pdev) ti_csi2rx_cleanup_ctx(&csi->ctx[i]); =20 ti_csi2rx_cleanup_notifier(csi); + unregister_pm_notifier(&csi->pm_notifier); + ti_csi2rx_cleanup_v4l2(csi); mutex_destroy(&csi->mutex); dma_free_coherent(csi->dev, csi->drain.len, csi->drain.vaddr, --=20 2.50.1