From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Hunter Subject: Re: [PATCH V2 1/3] mmc: core: Add a facility to "pause" re-tuning Date: Tue, 10 May 2016 16:03:14 +0300 Message-ID: <5731DC12.4090906@intel.com> References: <1462361893-11897-1-git-send-email-adrian.hunter@intel.com> <1462361893-11897-2-git-send-email-adrian.hunter@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mga11.intel.com ([192.55.52.93]:11168 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751229AbcEJNHI (ORCPT ); Tue, 10 May 2016 09:07:08 -0400 In-Reply-To: Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Ulf Hansson Cc: linux-mmc , Tomas Winkler On 10/05/16 15:24, Ulf Hansson wrote: > On 4 May 2016 at 13:38, Adrian Hunter wrote: >> Re-tuning is not possible when switched to the RPMB >> partition. However re-tuning should not be needed >> if re-tuning is done immediately before switching, >> a small set of operations is done, and then we >> immediately switch back to the main partition. >> >> To ensure that re-tuning can't be done for a short >> while, add a facility to "pause" re-tuning. >> >> The existing facility to hold / release re-tuning >> is used but it also flags re-tuning as needed to cause >> re-tuning before the next command (which will be the >> switch to RPMB). >> >> We also need to "unpause" in the recovery path, which >> is catered for by adding it to mmc_retune_disable(). >> >> Signed-off-by: Adrian Hunter >> --- >> drivers/mmc/core/host.c | 22 ++++++++++++++++++++++ >> include/linux/mmc/host.h | 4 ++++ >> 2 files changed, 26 insertions(+) >> >> diff --git a/drivers/mmc/core/host.c b/drivers/mmc/core/host.c >> index e0a3ee16c0d3..302e5858755a 100644 >> --- a/drivers/mmc/core/host.c >> +++ b/drivers/mmc/core/host.c >> @@ -68,8 +68,30 @@ void mmc_retune_enable(struct mmc_host *host) >> jiffies + host->retune_period * HZ); >> } >> >> +/* >> + * Pause re-tuning for a small set of operations. The pause begins after the >> + * next command and after first doing re-tuning. >> + */ >> +void mmc_retune_pause(struct mmc_host *host) >> +{ >> + if (!host->retune_paused) { >> + host->retune_paused = 1; >> + mmc_retune_needed(host); >> + mmc_retune_hold(host); >> + } >> +} >> + > > When the mmc block device driver is built as a module, this doesn't > build. I will drop the series from my next branch to sort this out. Oops. Sorry! > Should we export these via EXPORT_SYMBOL_GPL, or implement them as > inline functions? They need to be exported. I tend to go with what else is in the same file i.e. host.c is exporting using EXPORT_SYMBOL() > > This also made me think about the SDIO/WLAN driver issue, during > system PM suspend/resume, which also needed temporary to disable > re-tuning. > > *If* we are going to export these, I want to make it works for the > SDIO case well... SDIO case is slightly different, and SDIO uses its own header file sdio_func.h. > > Kind regards > Uffe > >> +void mmc_retune_unpause(struct mmc_host *host) >> +{ >> + if (host->retune_paused) { >> + host->retune_paused = 0; >> + mmc_retune_release(host); >> + } >> +} >> + >> void mmc_retune_disable(struct mmc_host *host) >> { >> + mmc_retune_unpause(host); >> host->can_retune = 0; >> del_timer_sync(&host->retune_timer); >> host->retune_now = 0; >> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h >> index 85800b48241f..45cde8cd39f2 100644 >> --- a/include/linux/mmc/host.h >> +++ b/include/linux/mmc/host.h >> @@ -329,6 +329,7 @@ struct mmc_host { >> unsigned int can_retune:1; /* re-tuning can be used */ >> unsigned int doing_retune:1; /* re-tuning in progress */ >> unsigned int retune_now:1; /* do re-tuning at next req */ >> + unsigned int retune_paused:1; /* re-tuning is temporarily disabled */ >> >> int rescan_disable; /* disable card detection */ >> int rescan_entered; /* used with nonremovable devices */ >> @@ -526,4 +527,7 @@ static inline void mmc_retune_recheck(struct mmc_host *host) >> host->retune_now = 1; >> } >> >> +void mmc_retune_pause(struct mmc_host *host); >> +void mmc_retune_unpause(struct mmc_host *host); >> + >> #endif /* LINUX_MMC_HOST_H */ >> -- >> 1.9.1 >> >