> -----Original Message----- > From: ath10k <ath10k-bounces@xxxxxxxxxxxxxxxxxxx> On Behalf Of Grant > Grundler > Sent: Saturday, May 4, 2019 2:01 AM > To: Wen Gong <wgong@xxxxxxxxxxxxxx> > Cc: linux-wireless@xxxxxxxxxxxxxxx; ath10k@xxxxxxxxxxxxxxxxxxx > 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 <wgong@xxxxxxxxxxxxxx> 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) Hi Grant, 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. > > cheers, > grant
