From mboxrd@z Thu Jan 1 00:00:00 1970 From: Evgeniy Didin Subject: Re: [PATCH 2/2 v3] mmc: dw_mmc: Fix the CTO overflow calculation for 32-bit systems Date: Mon, 26 Feb 2018 17:14:26 +0000 Message-ID: <1519665265.31245.6.camel@synopsys.com> References: <20180226143413.44134-1-Evgeniy.Didin@synopsys.com> <20180226143413.44134-3-Evgeniy.Didin@synopsys.com> <1519658060.31245.4.camel@synopsys.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: Content-Language: en-US Content-ID: Sender: linux-kernel-owner@vger.kernel.org To: "andy.shevchenko@gmail.com" , "Evgeniy.Didin@synopsys.com" Cc: "linux-kernel@vger.kernel.org" , "Alexey.Brodkin@synopsys.com" , "linux-mmc@vger.kernel.org" , "dianders@chromium.org" , "Vineet.Gupta1@synopsys.com" , "Eugeniy.Paltsev@synopsys.com" , "linux-snps-arc@lists.infradead.org" , "stable@vger.kernel.org" , "ulf.hansson@linaro.org" List-Id: linux-mmc@vger.kernel.org T24gTW9uLCAyMDE4LTAyLTI2IGF0IDE4OjUzICswMjAwLCBBbmR5IFNoZXZjaGVua28gd3JvdGU6 DQo+IE9uIE1vbiwgRmViIDI2LCAyMDE4IGF0IDU6MTQgUE0sIEV2Z2VuaXkgRGlkaW4NCj4gPEV2 Z2VuaXkuRGlkaW5Ac3lub3BzeXMuY29tPiB3cm90ZToNCj4gPiBPbiBNb24sIDIwMTgtMDItMjYg YXQgMTY6MzkgKzAyMDAsIEFuZHkgU2hldmNoZW5rbyB3cm90ZToNCj4gPiA+IE9uIE1vbiwgRmVi IDI2LCAyMDE4IGF0IDQ6MzQgUE0sIEV2Z2VuaXkgRGlkaW4NCj4gPiA+IDxFdmdlbml5LkRpZGlu QHN5bm9wc3lzLmNvbT4gd3JvdGU6DQo+ID4gPiA+IEluIGNvbW1pdCA0YzIzNTdmNTdkZDUgKCJt bWM6IGR3X21tYzogRml4IHRoZSBDVE8gdGltZW91dCBjYWxjdWxhdGlvbiIpDQo+ID4gPiA+IGhh dmUgYmVlbiBtYWRlIGNoYW5nZXMgd2hpY2ggY2FuIGNhdXNlIG11bHRpcGx5IG92ZXJmbG93IGZv ciAzMi1iaXQgc3lzdGVtcy4NCj4gPiA+ID4gVGhlIHZhbHVlIG9mIGN0b19tcyBpcyBsb3dlciB0 aGUgZHJ0b19tcywgYnV0IG5ldmVydGhlbGVzcyBvdmVyZmxvdyBjYW4gb2NjdXIuDQo+ID4gPiA+ IExldHMgY2FzdCB0aGlzIG11bHRpcGx5IHRvIHU2NCB0eXBlIHdoaWNoIHByZXZlbnRzIG92ZXJm bG93Lg0KPiA+ID4gPiAtwqDCoMKgwqDCoMKgwqBjdG9fbXMgPSBESVZfUk9VTkRfVVAoTVNFQ19Q RVJfU0VDICogY3RvX2Nsa3MgKiBjdG9fZGl2LCBob3N0LT5idXNfaHopOw0KPiA+ID4gPiArDQo+ ID4gPiA+ICvCoMKgwqDCoMKgwqDCoGN0b19tcyA9IERJVl9ST1VORF9VUCgodTY0KU1TRUNfUEVS X1NFQyAqIGN0b19jbGtzICogY3RvX2RpdiwgaG9zdC0+YnVzX2h6KTsNCj4gPiA+IA0KPiA+ID4g SUlSQywgc29tZW9uZSBjb21tZW50ZWQgb24gdGhpcyBvciBzaW1pbGFyLCBpLmUuDQo+ID4gPiAN Cj4gPiA+IERJVl9ST1VORF9VUF9VTEwoKSA/DQo+ID4gDQo+ID4gU3dpdGNoIERJVl9ST1VORF9V UCBtYWNybyB0byBESVZfUk9VTkRfVVBfVUxMIGlzIG5vdCByZWFzb25hYmxlDQo+ID4gYmVjYXVz ZSBvdmVyZmxvdyBoYXBwZW5zIG9uIG11bHRpcGx5IGFuZCBESVZfUk9VTkRfVVBfVUxMIGhlbHBz DQo+ID4gd2l0aCBzdW0gb3ZlcmZsb3cuDQo+IA0KPiBEaWQgeW91IHRyeSB0byBjb21waWxlIHlv dXIgY29kZSBmb3IgMzItYml0IHRhcmdldD8NClllcywgd2UgaGF2ZSBjb21waWxlZCBjb2RlIGZv ciAzMi1iaXQgc3lzdGVtLsKgDQpJIGFtIHdvbmRlcmluZyB3aHkgYXJlIHlvdSBhc2tpbmcgdGhh dD8NCg0KLS0NCkJlc3QgcmVnYXJkcywNCkV2Z2VuaXkgRGlkaW4= From mboxrd@z Thu Jan 1 00:00:00 1970 From: Evgeniy.Didin@synopsys.com (Evgeniy Didin) Date: Mon, 26 Feb 2018 17:14:26 +0000 Subject: [PATCH 2/2 v3] mmc: dw_mmc: Fix the CTO overflow calculation for 32-bit systems In-Reply-To: References: <20180226143413.44134-1-Evgeniy.Didin@synopsys.com> <20180226143413.44134-3-Evgeniy.Didin@synopsys.com> <1519658060.31245.4.camel@synopsys.com> List-ID: Message-ID: <1519665265.31245.6.camel@synopsys.com> To: linux-snps-arc@lists.infradead.org On Mon, 2018-02-26@18:53 +0200, Andy Shevchenko wrote: > On Mon, Feb 26, 2018 at 5:14 PM, Evgeniy Didin > wrote: > > On Mon, 2018-02-26@16:39 +0200, Andy Shevchenko wrote: > > > On Mon, Feb 26, 2018 at 4:34 PM, Evgeniy Didin > > > wrote: > > > > In commit 4c2357f57dd5 ("mmc: dw_mmc: Fix the CTO timeout calculation") > > > > have been made changes which can cause multiply overflow for 32-bit systems. > > > > The value of cto_ms is lower the drto_ms, but nevertheless overflow can occur. > > > > Lets cast this multiply to u64 type which prevents overflow. > > > > -???????cto_ms = DIV_ROUND_UP(MSEC_PER_SEC * cto_clks * cto_div, host->bus_hz); > > > > + > > > > +???????cto_ms = DIV_ROUND_UP((u64)MSEC_PER_SEC * cto_clks * cto_div, host->bus_hz); > > > > > > IIRC, someone commented on this or similar, i.e. > > > > > > DIV_ROUND_UP_ULL() ? > > > > Switch DIV_ROUND_UP macro to DIV_ROUND_UP_ULL is not reasonable > > because overflow happens on multiply and DIV_ROUND_UP_ULL helps > > with sum overflow. > > Did you try to compile your code for 32-bit target? Yes, we have compiled code for 32-bit system.? I am wondering why are you asking that? -- Best regards, Evgeniy Didin