From mboxrd@z Thu Jan 1 00:00:00 1970 From: nick Subject: Re: Weird/Unneeded call to msleep in exynos_mipi_dsi_wr_data in exynos_mipi_dsi_common.c Date: Thu, 18 Dec 2014 08:35:10 -0500 Message-ID: <5492D80E.3010906@gmail.com> References: <54920A54.2060608@gmail.com> <5492ABE7.1060900@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <5492ABE7.1060900@samsung.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: =?UTF-8?B?S3J6eXN6dG9mIEtvesWCb3dza2k=?= , inki.dae@samsung.com Cc: linux-fbdev@vger.kernel.org, linux-samsung-soc@vger.kernel.org, dh09.lee@samsung.com, linux-kernel@vger.kernel.org, kyungmin.park@samsung.com, tomi.valkeinen@ti.com, kgene@kernel.org, plagnioj@jcrosoft.com, linux-arm-kernel@lists.infradead.org List-Id: linux-samsung-soc@vger.kernel.org S3J6eXN6dG9mLApJZiB3ZSBsb29rIGF0IHRoZSBjb2RlIGZvciB0aGlzIGZ1bmN0aW9uLCBpdCBh bHJlYWR5IGlzIGhhbmRsaW5nIHRoZSBkYXRhIGNvcnJlY3RseS4gSW4gYWRkaXRpb24gIHRoZSBs b2NrcyAKc2VlbSB0byBiZSBiZXR0ZXIgcHJvdGVjdGlvbiB0aGVuIG1zbGVlcC4gRnVydGhlciBt b3JlIGlzIG5vIHJlYXNvbiBmb3IgdGhpcyBkZWxheSBhcyB3ZSBhcmUgbmVpdGhlciByZXNldHRp bmcgCnRoZSBoYXJkd2FyZSBvciB3YWl0aW5nIGZvciB0aGUgaGFyZHdhcmUgaGVyZSBzbyB3aHkg aXMgaXQgbmVlZGVkPyBJIGRvbid0IGhhdmUgRXh5bm9zIGJhc2VkIGhhcmR3YXJlIGx5aW5nCmFy b3VuZCB0aHJvdWdoIHRvIHRlc3QgaXQuCk5pY2sKT24gMjAxNC0xMi0xOCAwNToyNiBBTSwgS3J6 eXN6dG9mIEtvesWCb3dza2kgd3JvdGU6Cj4gT24gMTcuMTIuMjAxNCAyMzo1NywgbmljayB3cm90 ZToKPj4gR3JlZXRpbmdzIEZlbGxvdyBNYWludGFpbmVycywKPj4gU29ycnkgaWYgSSB3YXN0aW5n IHlvdXIgdGltZSBidXQgaXQgc2VlbXMgdGhlcmUgaXMgYSB1bm5lZWRlZCBjYWxsIHRvIG1zbGVl cAo+IAo+IEhpLAo+IAo+IDEuIFBsZWFzZSBkZXNjcmliZSBleGFjdGx5IHdoeSBkbyB5b3UgdGhp bmsgdGhpcyBpcyBub3QgbmVlZGVkLgo+IDIuIERvIHlvdSBoYXZlIEV4eW5vcy1iYXNlZCBoYXJk d2FyZSB0byB0ZXN0IHlvdXIgY2hhbmdlcz8KPiAKPiBCZXN0IHJlZ2FyZHMsCj4gS3J6eXN6dG9m Cj4gCj4+IGFuZCByYXRoZXIgdHJpdmlhbCBmaXggbWUgdG8gZml4IGluIHRoZSBmaWxlLGV4eW5v c19taXBpX2RzaV9jb21tb24uYyBmb3IgdGhlIGZ1bmN0aW9uLGV4eW5vc19taXBpX2RzaV93cl9k YXRhIC4gSWYgdGhlcmUgaXMgYSB2YWxpZCByZWFzb24gZm9yIHRoaXMgY2FsbCBwbGVhc2UgbGV0 IG1lIGtub3duIHdoZW4gYW55IG9mIHlvdSAgaGF2ZSBzb21lIGZyZWUgdGltZS4gT3RoZXJ3aXNl IEkgd2lsbCBzZW5kIGluIGEgcGF0Y2ggdG8gcmVtb3ZlIHRoaXMgdW5uZWVkZWQKPj4gY2FsbCB0 byBtc2xlZXAuCj4+IFRoYW5rcywKPj4gTmljayAgCj4gCj4gCgpfX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fXwpsaW51eC1hcm0ta2VybmVsIG1haWxpbmcgbGlz dApsaW51eC1hcm0ta2VybmVsQGxpc3RzLmluZnJhZGVhZC5vcmcKaHR0cDovL2xpc3RzLmluZnJh ZGVhZC5vcmcvbWFpbG1hbi9saXN0aW5mby9saW51eC1hcm0ta2VybmVsCg== From mboxrd@z Thu Jan 1 00:00:00 1970 From: xerofoify@gmail.com (nick) Date: Thu, 18 Dec 2014 08:35:10 -0500 Subject: Weird/Unneeded call to msleep in exynos_mipi_dsi_wr_data in exynos_mipi_dsi_common.c In-Reply-To: <5492ABE7.1060900@samsung.com> References: <54920A54.2060608@gmail.com> <5492ABE7.1060900@samsung.com> Message-ID: <5492D80E.3010906@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Krzysztof, If we look at the code for this function, it already is handling the data correctly. In addition the locks seem to be better protection then msleep. Further more is no reason for this delay as we are neither resetting the hardware or waiting for the hardware here so why is it needed? I don't have Exynos based hardware lying around through to test it. Nick On 2014-12-18 05:26 AM, Krzysztof Koz?owski wrote: > On 17.12.2014 23:57, nick wrote: >> Greetings Fellow Maintainers, >> Sorry if I wasting your time but it seems there is a unneeded call to msleep > > Hi, > > 1. Please describe exactly why do you think this is not needed. > 2. Do you have Exynos-based hardware to test your changes? > > Best regards, > Krzysztof > >> and rather trivial fix me to fix in the file,exynos_mipi_dsi_common.c for the function,exynos_mipi_dsi_wr_data . If there is a valid reason for this call please let me known when any of you have some free time. Otherwise I will send in a patch to remove this unneeded >> call to msleep. >> Thanks, >> Nick > >