From mboxrd@z Thu Jan 1 00:00:00 1970 From: Aaron Lu Subject: Re: [PATCH V2] sdhci: only reprogram retuning timer when flag is set Date: Tue, 12 Nov 2013 14:49:29 +0800 Message-ID: <5281CF79.1040803@intel.com> References: <1383821960-2533-1-git-send-email-arend@broadcom.com> <1384163395-27038-1-git-send-email-arend@broadcom.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mga09.intel.com ([134.134.136.24]:6522 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751255Ab3KLGsk (ORCPT ); Tue, 12 Nov 2013 01:48:40 -0500 In-Reply-To: <1384163395-27038-1-git-send-email-arend@broadcom.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Arend van Spriel , Chris Ball Cc: linux-mmc@vger.kernel.org On 11/11/2013 05:49 PM, Arend van Spriel wrote: > When the host->tuning_count is zero it means that the > retuning is disabled. This is checked on the first > run of sdhci_execute_tuning() by the if statement below: > > if (!(host->flags & SDHCI_NEEDS_RETUNING) && host->tuning_count && > (host->tuning_mode == SDHCI_TUNING_MODE_1)) { > > So only when tuning_count is non-zero it will set the host > flag SDHCI_USING_RETUNING_TIMER. The else statement is only > for re-programming the timer, which means that flag must be > set. Because that is not checked the else statement is executed > in the first run when tuning_count is zero. > > This was seen on a host controller which indicated > SDHCI_TUNING_MODE_1 (0) and tuning_count being zero. Suspect > that (one of) these registers is not properly set. > > Signed-off-by: Arend van Spriel Reviewed-by: Aaron Lu -Aaron > --- > This patch applies to the mmc-next branch. > > V2: > - add more explanation to the commit message > - check host flag SDHCI_USING_RETUNING_TIMER > --- > drivers/mmc/host/sdhci.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c > index bd8a098..5974599 100644 > --- a/drivers/mmc/host/sdhci.c > +++ b/drivers/mmc/host/sdhci.c > @@ -2014,7 +2014,7 @@ out: > host->tuning_count * HZ); > /* Tuning mode 1 limits the maximum data length to 4MB */ > mmc->max_blk_count = (4 * 1024 * 1024) / mmc->max_blk_size; > - } else { > + } else if (host->flags & SDHCI_USING_RETUNING_TIMER) { > host->flags &= ~SDHCI_NEEDS_RETUNING; > /* Reload the new initial value for timer */ > if (host->tuning_mode == SDHCI_TUNING_MODE_1) >