Hi Choi, The method "Save/restore clock source register - CLK_SRC_TOP3" was suggested as well as preferred by our hardware team. Would it be possible to give more information on this alternate method ? On Fri, Dec 21, 2012 at 7:07 AM, jonghwan Choi <jhbird.choi@xxxxxxxxx> wrote: > Hi~ > > This code should be changed. > > I insert this code (save/restore clock source register - CLK_SRC_TOP3) > temporary. > > But we removed this code. And we use another method to fix it. > > I think this is not right way. > > Thanks. > > > > On Fri, Dec 21, 2012 at 6:06 AM, <tomasz.figa@xxxxxxxxx> wrote: >> >> Hi Prasanna, >> >> On Thursday 20 of December 2012 17:56:18 Prasanna Kumar wrote: >> > This patch adds a software workaround to the hardware >> > problem found in exynos5 while powergating. >> > >> > It is observed that CLK_TOP_SRC3 register gets modified if >> > the G-Scaler/MFC devices are power gated. The clock for G-Scaler gets >> > set to XXTI which results in the device running very slow . >> > A big drop in performance is noticed whilerunning the video. >> > This issue also occurs while powergating MFC. >> > >> > The value of clock source register is restored once the powergating >> > operation is completed. >> >> Is the problem really related to power gating at all? From what you >> described in comment in the code, it seems like it's a problem with >> suspend/resume, not power gating, so it should be rather saved on suspend >> and restored on resume. Please recheck clock save/restore part of power >> management code. >> >> Altering clock configuration registers from power domain code looks really >> ugly... >> >> Best regards, >> Tomasz Figa >> >> -- >> To unsubscribe from this list: send the line "unsubscribe >> linux-samsung-soc" in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel > -- Thanks Prasanna Kumar -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
 |