From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?Q?M=c3=b4she_van_der_Sterre?= Subject: Re: [PATCH 2/2] efifb: Copy the ACPI BGRT boot graphics to the framebuffer Date: Mon, 18 Jun 2018 10:53:30 +0200 Message-ID: References: <20180617153235.16219-1-hdegoede@redhat.com> <20180617153235.16219-3-hdegoede@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <20180617153235.16219-3-hdegoede@redhat.com> Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Hans de Goede Cc: linux-efi@vger.kernel.org, linux-fbdev@vger.kernel.org, Bartlomiej Zolnierkiewicz , dri-devel@lists.freedesktop.org, Ard Biesheuvel List-Id: linux-efi@vger.kernel.org SGkgSGFucywKCk9uIDA2LzE3LzIwMTggMDU6MzIgUE0sIEhhbnMgZGUgR29lZGUgd3JvdGU6Cj4g T24gc3lzdGVtcyB3aGVyZSBmYmNvbiBpcyBjb25maWd1cmVkIGZvciBkZWZlcnJlZCBjb25zb2xl IHRha2VvdmVyLCB0aGUKPiBpbnRlbmQgaXMgZm9yIHRoZSBmcmFtZWJ1ZmZlciB0byBzaG93IHRo ZSBib290IGdyYXBoaWNzIChlLmcgYSB2ZW5kb3IKPiBsb2dvKSB1bnRpbCBzb21lIG1lc3NhZ2Ug KGUuZy4gYW4gZXJyb3IpIGlzIHByaW50ZWQgb3IgYSBncmFwaGljYWwKPiBzZXNzaW9uIHRha2Vz IG92ZXIuCj4gCj4gU29tZSBmaXJtd2FyZSBob3dldmVyIHJlbGllcyBvbiB0aGUgT1MgdG8gc2hv dyB0aGUgYm9vdCBncmFwaGljcwo+IChpbmRpY2F0ZWQgYnkgYmdydF90YWIuc3RhdHVzIGJlaW5n IDApIGFuZCB0aGUgYm9vdCBncmFwaGljcyBtYXkgaGF2ZQo+IGJlZW4gZGVzdHJveWVkIGJ5IGUu Zy4gdGhlIGdydWIgYm9vdCBtZW51LgoKSXQgbWF5IGJlIGNsZWFyZXIgdG8ganVzdCBzYXkgdGhh dCB0aGUgYm9vdCBncmFwaGljcyBtYXkgaGF2ZSBiZWVuIGRlc3Ryb3llZC4gVGhlIHJlZmVyZW5j ZSB0byB0aGUgc3RhdHVzIGZpZWxkIGFuZCBmaXJtd2FyZSBleHBlY3RhdGlvbnMgb25seSBjb25m dXNlcyB0aGUgaW50ZW50aW9uIG9mIHRoaXMgcGF0Y2gsIGltaG8uCihUaGlzIHRpZXMgaW4gdG8g d2hhdCBJIHNheSBiZWxvdykKCj4gVGhpcyBwYXRjaCBhZGRzIHN1cHBvcnQgdG8gZWZpZmIgdG8g c2hvdyB0aGUgYm9vdCBncmFwaGljcyBhbmQKPiBhdXRvbWF0aWNhbGx5IGVuYWJsZXMgdGhpcyB3 aGVuIGZiY29uIGlzIGNvbmZpZ3VyZWQgZm9yIGRlZmVycmVkCj4gY29uc29sZSB0YWtlb3Zlci4K PiAKPiArCS8qCj4gKwkgKiBXZSBkbyBub3QgY2hlY2sgYmdydF90YWIuc3RhdHVzIGhlcmUgYmVj YXVzZSB0aGlzIHNlZW1zIHRvIG9ubHkKPiArCSAqIHJlZmxlY3QgaWYgdGhlIGZpcm13YXJlIGhh cyBzaG93biB0aGUgYm9vdCBncmFwaGljcyBhdCBhbGwsIGlmIGl0Cj4gKwkgKiBsYXRlciBnb3Qg ZGVzdHJveWVkIGJ5IHNvbWV0aGluZyBzdGF0dXMgd2lsbCBzdGlsbCBiZSAxLgo+ICsJICogU2lu Y2Ugd2UgZHJhdyB0aGUgZXhhY3Qgc2FtZSBncmFwaGljIGF0IHRoZSBleGFjdCBzYW1lIHBsYWNl IHRoaXMKPiArCSAqIHdpbGwgbm90IGxlYWQgdG8gYW55IHRlYXJpbmcgaWYgdGhlIGJvb3QgZ3Jh cGhpYyBpcyBhbHJlYWR5IHRoZXJlLgo+ICsJICovCgpJIGFncmVlIHRoYXQgaWdub3JpbmcgYmdy dF90YWIuc3RhdHVzIGlzIHRoZSBhYnNvbHV0ZSBiZXN0IG9wdGlvbi4KClRoZSBzdGF0dXMgKHZh bGlkLWJpdCkgY2FuLCBpbiB0aGUgcmVhbCB3b3JsZCwgYmUgYW55IHZhbHVlIHdpdGggYW55IG1l YW5pbmcuCkkgY2hlY2tlZCB0aGlzIG9uIGEgZmV3IG1hY2hpbmVzIGFzIHBhcnQgb2YgY29tbWl0 IDY2ZGJlOTljZmUzMC4KIC0gTXkgd29ya3N0YXRpb24gYWx3YXlzIGhhcyAwLgogLSBBbiBvbGQg c2VydmVyIHRoYXQgSSBjaGVja2VkIGFsd2F5cyBoYXMgMS4KIC0gTXkgbGFwdG9wIGhhcyAxIGlm IHRoZSBib290IGlzIHVuaW50ZXJydXB0ZWQsIDAgaWYgSSByZXF1ZXN0IHRoZSBVRUZJIGJvb3Qg bWVudS4KClNvLCBJIGhhdmUgdGhlIHNhbWUgcmVzZXJ2YXRpb24gYWJvdXQgdGhpcyBjb21tZW50 IGFzIEkgaGF2ZSBhYm91dCB0aGUgY29tbWl0IG1lc3NhZ2UuIEltaG8sIHNpbXBseSBtZW50aW9u aW5nIHRoYXQgdGhlIHN0YXR1cyBmaWVsZCBjYW5ub3QgYmUgcmVsaWVkIHVwb24gKGluIGFueSBj YXNlKSwgd291bGQgZ2V0IHRoZSBwb2ludCBhY3Jvc3MuCl9fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fCmRyaS1kZXZlbCBtYWlsaW5nIGxpc3QKZHJpLWRldmVs QGxpc3RzLmZyZWVkZXNrdG9wLm9yZwpodHRwczovL2xpc3RzLmZyZWVkZXNrdG9wLm9yZy9tYWls bWFuL2xpc3RpbmZvL2RyaS1kZXZlbAo= From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?Q?M=c3=b4she_van_der_Sterre?= Date: Mon, 18 Jun 2018 08:53:30 +0000 Subject: Re: [PATCH 2/2] efifb: Copy the ACPI BGRT boot graphics to the framebuffer Message-Id: List-Id: References: <20180617153235.16219-1-hdegoede@redhat.com> <20180617153235.16219-3-hdegoede@redhat.com> In-Reply-To: <20180617153235.16219-3-hdegoede@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Hans de Goede Cc: linux-efi@vger.kernel.org, linux-fbdev@vger.kernel.org, Bartlomiej Zolnierkiewicz , dri-devel@lists.freedesktop.org, Ard Biesheuvel Hi Hans, On 06/17/2018 05:32 PM, Hans de Goede wrote: > On systems where fbcon is configured for deferred console takeover, the > intend is for the framebuffer to show the boot graphics (e.g a vendor > logo) until some message (e.g. an error) is printed or a graphical > session takes over. > > Some firmware however relies on the OS to show the boot graphics > (indicated by bgrt_tab.status being 0) and the boot graphics may have > been destroyed by e.g. the grub boot menu. It may be clearer to just say that the boot graphics may have been destroyed. The reference to the status field and firmware expectations only confuses the intention of this patch, imho. (This ties in to what I say below) > This patch adds support to efifb to show the boot graphics and > automatically enables this when fbcon is configured for deferred > console takeover. > > + /* > + * We do not check bgrt_tab.status here because this seems to only > + * reflect if the firmware has shown the boot graphics at all, if it > + * later got destroyed by something status will still be 1. > + * Since we draw the exact same graphic at the exact same place this > + * will not lead to any tearing if the boot graphic is already there. > + */ I agree that ignoring bgrt_tab.status is the absolute best option. The status (valid-bit) can, in the real world, be any value with any meaning. I checked this on a few machines as part of commit 66dbe99cfe30. - My workstation always has 0. - An old server that I checked always has 1. - My laptop has 1 if the boot is uninterrupted, 0 if I request the UEFI boot menu. So, I have the same reservation about this comment as I have about the commit message. Imho, simply mentioning that the status field cannot be relied upon (in any case), would get the point across.