From mboxrd@z Thu Jan 1 00:00:00 1970 From: Heiko Stuebner Subject: Re: [PATCH] drm/rockchip: Don't use spin_lock_irqsave in interrupt context Date: Sat, 10 Feb 2018 17:23:06 +0100 Message-ID: <1742402.LPvxsQ5ymm@phil> References: <20180210143501.30407-1-marc.zyngier@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <20180210143501.30407-1-marc.zyngier@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Marc Zyngier Cc: David Airlie , linux-rockchip@lists.infradead.org, Mark Yao , dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org List-Id: linux-rockchip.vger.kernel.org SGkgTWFyYywKCkFtIFNhbXN0YWcsIDEwLiBGZWJydWFyIDIwMTgsIDE1OjM1OjAxIENFVCBzY2hy aWViIE1hcmMgWnluZ2llcjoKPiBUaGUgcm9ja2NoaXAgRFJNIGRyaXZlciBpcyBxdWl0ZSBjYXJl ZnVsIHRvIGRpc2FibGUgaW50ZXJydXB0cwo+IHdoZW4gdGFraW5nIGEgbG9jayB0aGF0IGlzIGFs c28gdGFrZW4gaW4gaW50ZXJydXB0IGNvbnRleHQsCj4gd2hpY2ggaXMgYSBnb29kIHRoaW5nLgo+ IAo+IFdoYXQgaXMgYSBiaXQgb3ZlciB0aGUgdG9wIGlzIHRvIHVzZSBzcGluX2xvY2tfaXJxc2F2 ZSB3aGVuCj4gYWxyZWFkeSBpbiBpbnRlcnJ1cHQgY29udGV4dCwgYXMgeW91IGNhbm5vdCB0YWtl IGFub3RoZXIKPiBpbnRlcnJ1cHQgYWdhaW4sIGFuZCBkaXNhYmxpbmcgaW50ZXJydXB0IGlzIGp1 c3QgcHVyZQo+IG92ZXJoZWFkLgo+IAo+IFN3aXRjaGluZyB0byB0aGUgbm9uIF9pcnFzYXZlIHZl cnNpb24gaW4gaW50ZXJydXB0IGNvbnRleHQgaXMKPiBtb3JlIGxvZ2ljYWwsIGFuZCBsZXNzIGhl YXZ5IGhhbmRlZC4KPiAKPiBTaWduZWQtb2ZmLWJ5OiBNYXJjIFp5bmdpZXIgPG1hcmMuenluZ2ll ckBhcm0uY29tPgoKcGxlYXNlIG5vdGUsIHRoYXQgd2UgaGFkIGEgbWFpbnRhaW5lciBzd2FwIGZv ciB0aGUgUm9ja2NoaXAgZHJtLWNvbXBvbmVudCwKd2hlcmUgU2FuZHkgcmVwbGFjZWQgTWFyayBb MF0gLi4uIHdpdGggbWUgYWN0aW5nIGFzIHNvcnQtb2YgKGFuZCBub3QgeWV0CnVwIHRvIHNwZWVk KSBiYWNrdXAuCgpTbyBJIGd1ZXNzIFJvY2tjaGlwIGRybSBwYXRjaGVzIHNob3VsZCBhbHNvIGlu Y2x1ZGUKCVNhbmR5IEh1YW5nIDxoamNAcm9jay1jaGlwcy5jb20+CgoKSGVpa28KClswXSBodHRw czovL2dpdC5rZXJuZWwub3JnL3B1Yi9zY20vbGludXgva2VybmVsL2dpdC90b3J2YWxkcy9saW51 eC5naXQvY29tbWl0Lz9pZD1iNDE1Yjc5NTI5MzkxYWJkMjliNmEzMGI5MzY5NzgyMWYwMWUwODJm CgoKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJpLWRl dmVsIG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8v bGlzdHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVsCg== From mboxrd@z Thu Jan 1 00:00:00 1970 From: heiko@sntech.de (Heiko Stuebner) Date: Sat, 10 Feb 2018 17:23:06 +0100 Subject: [PATCH] drm/rockchip: Don't use spin_lock_irqsave in interrupt context In-Reply-To: <20180210143501.30407-1-marc.zyngier@arm.com> References: <20180210143501.30407-1-marc.zyngier@arm.com> Message-ID: <1742402.LPvxsQ5ymm@phil> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Hi Marc, Am Samstag, 10. Februar 2018, 15:35:01 CET schrieb Marc Zyngier: > The rockchip DRM driver is quite careful to disable interrupts > when taking a lock that is also taken in interrupt context, > which is a good thing. > > What is a bit over the top is to use spin_lock_irqsave when > already in interrupt context, as you cannot take another > interrupt again, and disabling interrupt is just pure > overhead. > > Switching to the non _irqsave version in interrupt context is > more logical, and less heavy handed. > > Signed-off-by: Marc Zyngier please note, that we had a maintainer swap for the Rockchip drm-component, where Sandy replaced Mark [0] ... with me acting as sort-of (and not yet up to speed) backup. So I guess Rockchip drm patches should also include Sandy Huang Heiko [0] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b415b79529391abd29b6a30b93697821f01e082f