From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sjoerd Simons Subject: Re: [PATCH] drm/exynos: resolve infinite loop issue on non multi-platform Date: Thu, 06 Nov 2014 18:08:40 +0100 Message-ID: <1415293720.31102.1.camel@collabora.co.uk> References: <1415283007-10096-1-git-send-email-inki.dae@samsung.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg="sha-1"; protocol="application/x-pkcs7-signature"; boundary="=-9bkhjQ5p+QvTTP6I2ZIc" Return-path: Received: from bhuna.collabora.co.uk ([93.93.135.160]:43105 "EHLO bhuna.collabora.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752448AbaKFRIo (ORCPT ); Thu, 6 Nov 2014 12:08:44 -0500 In-Reply-To: <1415283007-10096-1-git-send-email-inki.dae@samsung.com> Sender: linux-samsung-soc-owner@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org To: Inki Dae Cc: airlied@linux.ie, dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org --=-9bkhjQ5p+QvTTP6I2ZIc Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2014-11-06 at 23:10 +0900, Inki Dae wrote: > This patch resovles the infinite loop issue incurred > when Exyno drm driver is enabled but all kms drivers > are disabled on Exynos board by returning -EPROBE_DEFER > only in case that there is kms device registered. It would be nice if you could explain in the commit message/comment why returning -EPROBE_DEFER causes an infinite loop and why it's the wrong thing to do in this case?=20 Even if you know this probe will never succeed in the future (so deferring is actually pointless), deferring really shouldn't trigger infinte loops in calling code >=20 > Signed-off-by: Inki Dae > --- > drivers/gpu/drm/exynos/exynos_drm_drv.c | 6 ++++++ > 1 file changed, 6 insertions(+) >=20 > diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/ex= ynos/exynos_drm_drv.c > index ecc86aa..14c6af7 100644 > --- a/drivers/gpu/drm/exynos/exynos_drm_drv.c > +++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c > @@ -488,6 +488,12 @@ static struct component_match *exynos_drm_match_add(= struct device *dev) > =20 > mutex_lock(&drm_component_lock); > =20 > + /* Do not retry to probe if there is no any kms driver regitered. */ > + if (list_empty(&drm_component_list)) { > + mutex_unlock(&drm_component_lock); > + return ERR_PTR(-ENODEV); > + } > + > list_for_each_entry(cdev, &drm_component_list, list) { > /* > * Add components to master only in case that crtc and --=-9bkhjQ5p+QvTTP6I2ZIc Content-Type: application/x-pkcs7-signature; name="smime.p7s" Content-Disposition: attachment; filename="smime.p7s" Content-Transfer-Encoding: base64 MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIUzDCCBsIw ggWqoAMCAQICEAoE3yF0XU0rjOozcgUAUOkwDQYJKoZIhvcNAQEFBQAwZTELMAkGA1UEBhMCVVMx FTATBgNVBAoTDERpZ2lDZXJ0IEluYzEZMBcGA1UECxMQd3d3LmRpZ2ljZXJ0LmNvbTEkMCIGA1UE AxMbRGlnaUNlcnQgQXNzdXJlZCBJRCBSb290IENBMB4XDTA2MTExMDAwMDAwMFoXDTIxMTExMDAw MDAwMFowYjELMAkGA1UEBhMCVVMxFTATBgNVBAoTDERpZ2lDZXJ0IEluYzEZMBcGA1UECxMQd3d3 LmRpZ2ljZXJ0LmNvbTEhMB8GA1UEAxMYRGlnaUNlcnQgQXNzdXJlZCBJRCBDQS0xMIIBIjANBgkq hkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEA6IItmfnKwkKVpYBzQHDSnlZUXKnE0kEGj8kz/E1FkVyB n+0snPgWWd+etSQVwpi5tHdJ3InECtqvy15r7a2wcTHrzzpADEZNk+yLejYIA6sMNP4YSYL+x8cx 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