From mboxrd@z Thu Jan 1 00:00:00 1970 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (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 3FFFAC88E6A for ; Mon, 14 Sep 2026 09:14:46 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 200ED10E172; Mon, 14 Sep 2026 09:14:45 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=kernel.org header.i=@kernel.org header.b="GNHRYfUJ"; dkim-atps=neutral Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by gabe.freedesktop.org (Postfix) with ESMTPS id A7B0410E189 for ; Mon, 14 Sep 2026 09:14:43 +0000 (UTC) Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 5782343923; Mon, 14 Sep 2026 09:14:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 023141F000FF; Mon, 14 Sep 2026 09:14:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789377283; bh=LrutReZ5R9lj/02OwAOFdnsGfMcThHjIY3yuMYn4ORw=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=GNHRYfUJUdoVjjWXzh++r4dV8YS5TozSqVqmo2Uv65sWYEd8pz20DEP8NFaPz/4mI kR/pe1ucZ5IlMoIV6bzklQn2rttLaZX/Oia3ZFz4660+7wlAgM0M/9JHU6yoVcqYWB nZ1HqJlZPUOSD7wwOWMoybF7EREtzRIivnGieuvRy9tyvfUHU0SyQwhyZd10kCJ7tW ehxUQyK1pY+Lsx36+jadIAFrY5xOK6Bs0H5JPllPWnsU2UUOwZMyOfkT/6nrtdloqZ RHfFyVi6cA2Mv5nxIw+VnyBeeSuAMW9cokP9Uyg0uaYZq+0/qaLaRLLgJ3ylGPkBR3 CWH3gLY+zUZDQ== From: sashiko-bot@kernel.org Subject: Re: [PATCH v6 2/6] drm/ssd130x: Change SSD133X color format to RGB565 from RGB332 To: "Amit Barzilai" Cc: dri-devel@lists.freedesktop.org, conor+dt@kernel.org, devicetree@vger.kernel.org, robh@kernel.org In-Reply-To: <20260914085931.66857-3-amit.barzilai22@gmail.com> References: <20260914085931.66857-1-amit.barzilai22@gmail.com> <20260914085931.66857-3-amit.barzilai22@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Mon, 14 Sep 2026 09:14:42 +0000 Message-Id: <20260914091443.023141F000FF@smtp.kernel.org> X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Thank you for your contribution! Sashiko AI review found 1 potential issue(= s) to consider: Pre-existing issues: - [High] Missing `fmtcnv_state` buffer reservation in `ssd133x_primary_plan= e_atomic_check` causes a `GFP_KERNEL` allocation in atomic context. -- commit 58733b43936278b0113cbbd363c279ece2464617 Author: Amit Barzilai drm/ssd130x: Change SSD133X color format to RGB565 from RGB332 SSD133X screens were driven at 8bpp RGB332 despite supporting 16bpp RGB565. Switch the SSD133X data path to RGB565. > diff --git a/drivers/gpu/drm/solomon/ssd130x.c b/drivers/gpu/drm/solomon/= ssd130x.c > index feec4933e3e6b..cbf77a74c4fa0 100644 > --- a/drivers/gpu/drm/solomon/ssd130x.c > +++ b/drivers/gpu/drm/solomon/ssd130x.c [ ... ] > @@ -978,17 +990,18 @@ static int ssd133x_fb_blit_rect(struct drm_framebuf= fer *fb, > struct drm_format_conv_state *fmtcnv_state) > { > struct ssd130x_device *ssd130x =3D drm_to_ssd130x(fb->dev); > - const struct drm_format_info *fi =3D drm_format_info(DRM_FORMAT_RGB332); > + const struct drm_format_info *fi; > unsigned int dst_pitch; > struct iosys_map dst; > =20 > + fi =3D drm_format_info(DRM_FORMAT_RGB565); > if (!fi) > return -EINVAL; > =20 > dst_pitch =3D drm_format_info_min_pitch(fi, 0, drm_rect_width(rect)); > =20 > iosys_map_set_vaddr(&dst, data_array); > - drm_fb_xrgb8888_to_rgb332(&dst, &dst_pitch, vmap, fb, rect, fmtcnv_stat= e); > + drm_fb_xrgb8888_to_rgb565be(&dst, &dst_pitch, vmap, fb, rect, fmtcnv_st= ate); [Severity: High] This is a pre-existing issue, but does this code cause a GFP_KERNEL allocat= ion in atomic context? When the screen is updated, ssd133x_primary_plane_atomic_update() (which ru= ns in atomic context) calls ssd133x_fb_blit_rect() which in turn calls drm_fb_xrgb8888_to_rgb565be(). This internally calls __drm_fb_xfrm(), which attempts a GFP_KERNEL allocati= on if the conversion buffer was not previously reserved: drivers/gpu/drm/drm_format_helper.c:__drm_fb_xfrm() { if (!vaddr_cached_hint) { stmp =3D drm_format_conv_state_reserve(state, sbuf_len, GFP_KERNEL); if (!stmp) return -ENOMEM; } } Because ssd133x_primary_plane_atomic_check() omits the drm_format_conv_state_reserve() call (unlike its ssd130x and ssd132x varian= ts): drivers/gpu/drm/solomon/ssd130x.c:ssd133x_primary_plane_atomic_check() { ... else if (!plane_state->visible) return 0; return 0; } Will this cause the allocation to be unconditionally executed in atomic con= text on the first frame update? --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20260914085931.6685= 7-1-amit.barzilai22@gmail.com?part=3D2