From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp.codeaurora.org ([198.145.29.96]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hNwV6-00060u-W0 for ath10k@lists.infradead.org; Tue, 07 May 2019 09:35:06 +0000 From: Kalle Valo Subject: Re: [PATCH] ath10k: remove mmc_hw_reset while hif power down References: <1556417825-13713-1-git-send-email-wgong@codeaurora.org> <36950ff25c0747629e60ccb68819e93a@aptaiexm02f.ap.qualcomm.com> Date: Tue, 07 May 2019 12:34:59 +0300 In-Reply-To: <36950ff25c0747629e60ccb68819e93a@aptaiexm02f.ap.qualcomm.com> (Wen Gong's message of "Tue, 7 May 2019 05:05:21 +0000") Message-ID: <87pnour4jg.fsf@codeaurora.org> MIME-Version: 1.0 List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "ath10k" Errors-To: ath10k-bounces+kvalo=adurom.com@lists.infradead.org To: Wen Gong Cc: Grant Grundler , "linux-wireless@vger.kernel.org" , Ulf Hansson , "ath10k@lists.infradead.org" , Wen Gong + Ulf to give comments from SDIO point of view Wen Gong writes: >> -----Original Message----- >> From: ath10k On Behalf Of Grant >> Grundler >> Sent: Saturday, May 4, 2019 2:01 AM >> To: Wen Gong >> Cc: linux-wireless@vger.kernel.org; ath10k@lists.infradead.org >> Subject: [EXT] Re: [PATCH] ath10k: remove mmc_hw_reset while hif power >> down >> >> [repeating comments I made in the gerrit review for Chrome OS : >> https://chromium- >> review.googlesource.com/c/chromiumos/third_party/kernel/+/1585667 >> ] >> >> On Sat, Apr 27, 2019 at 7:17 PM Wen Gong wrote: >> > >> > For sdio 3.0 chip, the clock will drop from 200M Hz to 50M Hz after load >> > ath10k driver, it is because mmc_hw_reset will reset the sdio's power, >> > then mmc will consider it as sdio 2.0 and drop the clock. >> >> Wen, >> 5468e784c0600551ca03263f5255a375c05f88e7 commit message gives >> reasons >> for adding the mmc_hw_reset() call. The commit message for removing >> gives different reason for removal. Both are good but second one is >> incomplete. >> >> The commit message for removal should ALSO explain why adding this >> call wasn't necessary in the first place OR move the call to a >> different code path. >> >> > Remove mmc_hw_reset will avoid the drop of clock. >> >> This commit message makes it clear the original patch introduced a new >> problem. But the original patch fixed a different problem and that >> this proposed change seems likely to re-introduce and the commit >> message should explain why that isn't true (or how the original was >> fixed differently) > > The mmc_hw_reset's effect depends on the hardware layout/configure > software's behavior, recently it will effect the clock of sdio for the > platform I used. And it will still work well without mmc_hw_reset for > the platform I Used currently. If sdio cannot work on other platform, > I think it can add flag in ath10k_hw_params_list for the platform to > call the mmc_hw_reset depends on the flag. I don't see how you can use ath10k_hw_params_list to separate SDIO controller functionality, I assume that's the real reason for difference of functionality? Maybe this is a bug on the SDIO controller? Ulf, what do you think? Any suggestions? Full discussion here: https://patchwork.kernel.org/patch/10920563/ -- Kalle Valo _______________________________________________ ath10k mailing list ath10k@lists.infradead.org http://lists.infradead.org/mailman/listinfo/ath10k