From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Tue, 02 Jun 2026 11:38:51 +0200 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1wULaF-001XUT-24 for lore@lore.pengutronix.de; Tue, 02 Jun 2026 11:38:51 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1wULaE-0001KG-6f for lore@pengutronix.de; Tue, 02 Jun 2026 11:38:51 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=fd17XyiErWkDcx+CTXOD5zVdXfhR4VTP9Sl+teR0JxI=; b=NHqT/zYYfDncLgKEEUnxwX04hO X09JURTeQeRNBxGPyyLRk76hCsPr61g+BJJfNuRH5gXS9NGOaxxH0yn/YWZXC9/MS/oE6QX3X9UAx w2gduOr3W79C3mGXGKHatf+X61BwPdBmQ5enyzyOURbm2P0QiwqIU0tcTUQTo89ks2mzGDg3APQml O3wrcc8N22oKqNz+wj3HA4RGvQ+fgtL++qjIj+UeCs5a79NaKjJCEXi8fxqCdG/NDm5GMKxCJCtsE 5w2+jXU9rMDXXAWwOAemA2eAWeAQGUX4VbsOnsPVxeJEYQb8iNvRcx8iev/VUSZS/YWe4/iFHff+z jM9v+ZfA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wULZE-0000000CgWL-40eD; Tue, 02 Jun 2026 09:37:48 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wULZC-0000000CgVY-15p4 for barebox@lists.infradead.org; Tue, 02 Jun 2026 09:37:47 +0000 Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=[127.0.0.1]) by metis.whiteo.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1wULZA-0001A5-KM; Tue, 02 Jun 2026 11:37:44 +0200 Message-ID: <679f1823-5edd-4a8f-8a8e-caf6db7dd483@pengutronix.de> Date: Tue, 2 Jun 2026 11:37:44 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Lucas Stach , Johannes Schneider , barebox@lists.infradead.org Cc: thomas.haemmerle@leica-geosystems.com References: <20260602040953.1060278-1-johannes.schneider@leica-geosystems.com> <20260602040953.1060278-7-johannes.schneider@leica-geosystems.com> <54467182b9e4f15a1ac068533e73aaac5f21bf46.camel@pengutronix.de> From: Ahmad Fatoum Content-Language: en-US, de-DE, de-BE In-Reply-To: <54467182b9e4f15a1ac068533e73aaac5f21bf46.camel@pengutronix.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260602_023746_383315_6CB24C54 X-CRM114-Status: GOOD ( 25.69 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-5.2 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH 6/6] video: imx-lcdif: drain write-combine buffer before LCDIF DMA reads pixels X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) On 6/2/26 10:12 AM, Lucas Stach wrote: > Am Dienstag, dem 02.06.2026 um 04:09 +0000 schrieb Johannes Schneider: >> From: Thomas Haemmerle >> >> The LCDIF framebuffer is allocated as Normal Non-Cacheable (write-combine) >> memory. After the splash command calls gu_screen_blit(), which copies the >> decoded PNG via memcpy() from a cached shadow buffer into the hardware >> framebuffer, writes may still reside in the CPU write buffer and not yet >> be visible to the LCDIF DMA engine. On hardware this manifests as >> partial or corrupted rendering — the bottom portion of the splash image >> renders black or shows garbage. >> >> Implement fb_damage() to execute a DSB SY barrier after each blit, >> ensuring all pending write-combine writes are committed to DRAM before >> the LCDIF reads the pixel data. >> >> Assisted-by: Claude:claude-sonnet-4-6 >> Signed-of-by: Thomas Haemmerle >> --- >> drivers/video/imx-lcdif.c | 13 +++++++++++++ >> 1 file changed, 13 insertions(+) >> >> diff --git a/drivers/video/imx-lcdif.c b/drivers/video/imx-lcdif.c >> index ae5976c771..8d9b40be0f 100644 >> --- a/drivers/video/imx-lcdif.c >> +++ b/drivers/video/imx-lcdif.c >> @@ -20,6 +20,7 @@ >> #include >> #include