Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757067AbbESPV0 (ORCPT ); Tue, 19 May 2015 11:21:26 -0400 Received: from mail-la0-f53.google.com ([209.85.215.53]:34264 "EHLO mail-la0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755856AbbESPVX (ORCPT ); Tue, 19 May 2015 11:21:23 -0400 MIME-Version: 1.0 In-Reply-To: <1431878106-30579-8-git-send-email-ygardi@codeaurora.org> References: <1431878106-30579-1-git-send-email-ygardi@codeaurora.org> <1431878106-30579-8-git-send-email-ygardi@codeaurora.org> Date: Wed, 20 May 2015 00:21:20 +0900 Message-ID: Subject: Re: [PATCH v1 07/10] scsi: ufs: introduce UFSHCD_QUIRK_DME_PEER_ACCESS_AUTO_MODE quirk From: Akinobu Mita To: Yaniv Gardi Cc: Jej B , Christoph Hellwig , LKML , "linux-scsi@vger.kernel.org" , linux-arm-msm@vger.kernel.org, Santosh Y , linux-scsi-owner@vger.kernel.org, Subhash Jadavani , dovl@codeaurora.org, Dolev Raviv , Vinayak Holikatti , "James E.J. Bottomley" Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2831 Lines: 62 2015-05-18 0:55 GMT+09:00 Yaniv Gardi : > Some UFS host controllers may only allow accessing the peer DME attribute > in AUTO mode (FAST AUTO or SLOW AUTO) hence we had added a quirk for > switching to AUTO power mode before accessing the peer DME attribute. > > Signed-off-by: Yaniv Gardi > > --- > drivers/scsi/ufs/ufshcd.c | 31 +++++++++++++++++++++++++++++++ > drivers/scsi/ufs/ufshcd.h | 7 +++++++ > 2 files changed, 38 insertions(+) > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > index a274df9..014f1c0 100644 > --- a/drivers/scsi/ufs/ufshcd.c > +++ b/drivers/scsi/ufs/ufshcd.c > @@ -188,6 +188,8 @@ static int ufshcd_host_reset_and_restore(struct ufs_hba *hba); > static irqreturn_t ufshcd_intr(int irq, void *__hba); > static int ufshcd_config_pwr_mode(struct ufs_hba *hba, > struct ufs_pa_layer_attr *desired_pwr_mode); > +static int ufshcd_change_power_mode(struct ufs_hba *hba, > + struct ufs_pa_layer_attr *pwr_mode); > > static inline int ufshcd_enable_irq(struct ufs_hba *hba) > { > @@ -2156,6 +2158,31 @@ int ufshcd_dme_get_attr(struct ufs_hba *hba, u32 attr_sel, > }; > const char *get = action[!!peer]; > int ret; > + struct ufs_pa_layer_attr orig_pwr_info; > + struct ufs_pa_layer_attr temp_pwr_info; > + bool pwr_mode_change = false; > + > + if (peer && (hba->quirks & UFSHCD_QUIRK_DME_PEER_ACCESS_AUTO_MODE)) { > + orig_pwr_info = hba->pwr_info; > + temp_pwr_info = orig_pwr_info; > + > + if (orig_pwr_info.pwr_tx == FAST_MODE || > + orig_pwr_info.pwr_rx == FAST_MODE) { > + temp_pwr_info.pwr_tx = FASTAUTO_MODE; > + temp_pwr_info.pwr_rx = FASTAUTO_MODE; > + pwr_mode_change = true; > + } else if (orig_pwr_info.pwr_tx == SLOW_MODE || > + orig_pwr_info.pwr_rx == SLOW_MODE) { > + temp_pwr_info.pwr_tx = SLOWAUTO_MODE; > + temp_pwr_info.pwr_rx = SLOWAUTO_MODE; > + pwr_mode_change = true; > + } > + if (pwr_mode_change) { > + ret = ufshcd_change_power_mode(hba, &temp_pwr_info); I'm a bit worried that this could cause an infinite recursion if someone adds ufshcd_dme_peer_get() in ufshcd_change_power_mode() for debugging or investigation. So isn't it better to add note in code comment, or detect infinite recursion? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/