From nobody Sun Apr 5 13:07:34 2026 Received: from ms.puri.sm (ms.puri.sm [135.181.196.210]) (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 AFA53345CA2 for ; Wed, 18 Feb 2026 18:00:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=135.181.196.210 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771437607; cv=none; b=mk8LEL8fKr2nJrFSvdFvQ5Qo0fRl3b/Ty8j/pBtdUe15aUN9blecwiWgLEJy+uCIBM03wO8S91o9I8PL/UzpfDtA4EXlQPGZCwZvI6/i+Da7NqRYhIJnvf4+NqBjNaGeD8CTdPdM/bP5kN+n47YPPeUIpIjO/5H361t+f3rRGtg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771437607; c=relaxed/simple; bh=hK2Hidrn3JSH5YVVXdg/+CyVKuFR4gUJBJGeUCnYDyI=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:To:Cc; b=PSRc/VCG/mb6cG41Ji1OdZml2KrwOgw6pMVVpFZBC9JPQ8C140+MdXRbE3JwOm5g0jxbisPK1gZxHpi7LdRtEFVdJZnefVtGkpw5JnuLI9PJBRfLmWJdyAROpL3Lw1DeiB5o6DZNin/1bufUrIdpG7aKN6MzklpTxS05S0LzA9Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=puri.sm; spf=pass smtp.mailfrom=puri.sm; dkim=pass (2048-bit key) header.d=puri.sm header.i=@puri.sm header.b=EuP5iims; arc=none smtp.client-ip=135.181.196.210 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=puri.sm Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=puri.sm Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=puri.sm header.i=@puri.sm header.b="EuP5iims" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=puri.sm; s=smtp2; t=1771437598; bh=hK2Hidrn3JSH5YVVXdg/+CyVKuFR4gUJBJGeUCnYDyI=; h=From:Date:Subject:To:Cc; b=EuP5iimsREVbP5XWCShyq1NHeEuDTDka9netTMiBfUKAqdb7cDVnWki1Y13Qa4pY7 XHwmwXomtLWegk91eeJvDSLfrPcKvwf9Rl2wu1m9wk1lPnUTc2Z4kGfywwGYwkeN0c 5OttrOO8GVY9Y1ENiurO4Stov0cib1qhVYdAuP3QW2PQEW2QhSui1YKCndXT+fKpln 20Vtka23bsEufXuoNb7ScB0EJ0AbseVlfXBRVkQQTEaPGSUdlZuTvjEpZwgL0dfR/2 mre+ZWB9+XbxL1vPRj9DHUdxvhR3PeWzObIyqy4G0ACJ5tvhmAQZ9hBw1q+wCGou7C SrEWMhDMjnrww== Received: from pliszka.localdomain (79.184.40.11.ipv4.supernova.orange.pl [79.184.40.11]) by ms.puri.sm (Postfix) with ESMTPSA id D5F9C1F6B7; Wed, 18 Feb 2026 09:59:56 -0800 (PST) From: Sebastian Krzyszkowiak Date: Wed, 18 Feb 2026 18:59:15 +0100 Subject: [PATCH] drm/bridge: nwl-dsi: Choose burst mode over non-burst with sync pulse 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: <20260218-nwl-dsi-burst-v1-1-6c30cb0585e4@puri.sm> X-B4-Tracking: v=1; b=H4sIAAAAAAAC/x3MQQrCQAxA0auUrA3OTKWoV5EuMtNoAzVK0qpQe ndHl2/x/wrOJuxwblYwfonLQyviroEykt4YZaiGFFIXUjyiviccXDAv5jPGtiuH0hKfKEBtnsZ X+fx/l746kzNmIy3j7zKJLr6/k89ssG1fkAFXHn4AAAA= X-Change-ID: 20260218-nwl-dsi-burst-136c4c3ae9a0 To: Andrzej Hajda , Neil Armstrong , Robert Foss , Laurent Pinchart , Jonas Karlman , Jernej Skrabec , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Simona Vetter Cc: kernel@puri.sm, dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, Sebastian Krzyszkowiak X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=2761; i=sebastian.krzyszkowiak@puri.sm; h=from:subject:message-id; bh=hK2Hidrn3JSH5YVVXdg/+CyVKuFR4gUJBJGeUCnYDyI=; b=owEBbQKS/ZANAwAKAejyNc8728P/AcsmYgBplf4cfRJECZIx5VKH+/F/6EnsNrisv3xn5faXT NKckJo0nA+JAjMEAAEKAB0WIQQi3Z+uAGoRQ1g2YXzo8jXPO9vD/wUCaZX+HAAKCRDo8jXPO9vD /4EjEAC/18/7T0lkTFdCXpxU26T/HH7MGlq5mPhSP0WJi9ERl+/vbHalI53kHtF5OYPAtZ5bs65 OFJkKoNkUEuD9r/+rrZ4g9FwLmb41AVmejhXChwB7FZldK7idvPtL8w01MTSrz8Dk6Ingln2XK5 lDC7MSPTB+AxxYECCWQmxILvr2P6ryrTUQoT5d+egtSlIduKDTB7s6WPZHyTnMlvRd1RaD+BViu tRriQtAG4aB0KMiXTTHkPdaGy0VUqtXZ9OwGWbtGMrRs/YPmSLaZbV0P4LLUEJ2Vq8YvYcdWCbH AD53lxr49IuQOv3nxs7O+pkcdB2jItNUnzlaXFRD99Ecqp20wQF/7IfjCfGUcfAQFDPD+HsTJJH kKPdCzge9+oWJTGAUZ9oy8eEsnYxtYN98Dm3LjKxNFjrGM+BDTtaqkzcvMklDo3A/6pK+I764HR 8zZkBh/6xmtQijHEKZj/9Uatr493ixxFhjuHCAz5Nh8WtZNlfA44eknXIpYKY6LXrv3gkeuxzwC b+jBf6odaSBBM7h0KKYpnDEeDmlcU7SeMcjBoSZYQCGzACycMW37LS9aTXm/JSir0pc7IYCgwME dju/SHrVWn9agBNbmzwJxBu702iKhL9vqyI4MX7bgYLlUEZuPES809tTaGFNWLmtA81YZ7NGtGh z+notORTObOiwYg== X-Developer-Key: i=sebastian.krzyszkowiak@puri.sm; a=openpgp; fpr=22DD9FAE006A11435836617CE8F235CF3BDBC3FF The driver refers to "burst mode with sync pulse" and seems to be coded in a way that assumes it's a thing. However, I couldn't find any source that would confirm its existence (aside of very eager to make it up LLMs). The datasheet allows to choose between three modes: - burst mode - non-burst mode with sync pulses - non-burst mode with sync events These three modes are also referenced across all sorts of MIPI DSI-related documentation over the Internet. Rename the define and default to burst mode, like other bridges tend to do. Signed-off-by: Sebastian Krzyszkowiak --- drivers/gpu/drm/bridge/nwl-dsi.c | 8 ++------ drivers/gpu/drm/bridge/nwl-dsi.h | 2 +- 2 files changed, 3 insertions(+), 7 deletions(-) diff --git a/drivers/gpu/drm/bridge/nwl-dsi.c b/drivers/gpu/drm/bridge/nwl-= dsi.c index 2f7429b24fc2..c1859a04db97 100644 --- a/drivers/gpu/drm/bridge/nwl-dsi.c +++ b/drivers/gpu/drm/bridge/nwl-dsi.c @@ -257,7 +257,6 @@ static int nwl_dsi_config_dpi(struct nwl_dsi *dsi) { u32 mode; int color_format; - bool burst_mode; int hfront_porch, hback_porch, vfront_porch, vback_porch; int hsync_len, vsync_len; =20 @@ -298,15 +297,12 @@ static int nwl_dsi_config_dpi(struct nwl_dsi *dsi) NWL_DSI_HSYNC_POLARITY_ACTIVE_HIGH : NWL_DSI_HSYNC_POLARITY_ACTIVE_LOW); =20 - burst_mode =3D (dsi->dsi_mode_flags & MIPI_DSI_MODE_VIDEO_BURST) && - !(dsi->dsi_mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE); - - if (burst_mode) { + if (dsi->dsi_mode_flags & MIPI_DSI_MODE_VIDEO_BURST) { nwl_dsi_write(dsi, NWL_DSI_VIDEO_MODE, NWL_DSI_VM_BURST_MODE); nwl_dsi_write(dsi, NWL_DSI_PIXEL_FIFO_SEND_LEVEL, 256); } else { mode =3D ((dsi->dsi_mode_flags & MIPI_DSI_MODE_VIDEO_SYNC_PULSE) ? - NWL_DSI_VM_BURST_MODE_WITH_SYNC_PULSES : + NWL_DSI_VM_NON_BURST_MODE_WITH_SYNC_PULSES : NWL_DSI_VM_NON_BURST_MODE_WITH_SYNC_EVENTS); nwl_dsi_write(dsi, NWL_DSI_VIDEO_MODE, mode); nwl_dsi_write(dsi, NWL_DSI_PIXEL_FIFO_SEND_LEVEL, diff --git a/drivers/gpu/drm/bridge/nwl-dsi.h b/drivers/gpu/drm/bridge/nwl-= dsi.h index 61e7d65cb1eb..c81edc58647b 100644 --- a/drivers/gpu/drm/bridge/nwl-dsi.h +++ b/drivers/gpu/drm/bridge/nwl-dsi.h @@ -123,7 +123,7 @@ #define NWL_DSI_RX_VC(x) FIELD_GET(GENMASK(23, 22), (x)) =20 /* DSI Video mode */ -#define NWL_DSI_VM_BURST_MODE_WITH_SYNC_PULSES 0 +#define NWL_DSI_VM_NON_BURST_MODE_WITH_SYNC_PULSES 0 #define NWL_DSI_VM_NON_BURST_MODE_WITH_SYNC_EVENTS BIT(0) #define NWL_DSI_VM_BURST_MODE BIT(1) =20 --- base-commit: 2961f841b025fb234860bac26dfb7fa7cb0fb122 change-id: 20260218-nwl-dsi-burst-136c4c3ae9a0 Best regards, --=20 Sebastian Krzyszkowiak