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Tue, 14 Oct 2025 04:35:11 +0000 (GMT) From: "Wonkon Kim" To: "'Bart Van Assche'" , , , , , In-Reply-To: Subject: RE: [PATCH] ufs: core: Initialize a variable mode for PA_PWRMODE Date: Tue, 14 Oct 2025 13:35:11 +0900 Message-ID: <065101dc3cc3$eda735c0$c8f5a140$@samsung.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Mailer: Microsoft Outlook 15.0 Thread-Index: AQFhT2clGfJ4dWcII9qWXyagEihcgwJWi3eIAdcMmwEC1X995AKKjmFatWp7pXA= Content-Language: ko X-CMS-MailID: 20251014043511epcas1p37bffc5c998bff21f27aba426deb77e95 X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" CMS-TYPE: 101P cpgsPolicy: CPGSC10-711,Y X-CFilter-Loop: Reflected X-CMS-RootMailID: 20251002070057epcas1p49ac487359f24f6813ba8f9f44bcf0924 References: <20251002070027.228638-1-wkon.kim@samsung.com> <4c894d68-7d0e-49a0-b582-477bcc7f351d@acm.org> <000001dc3c1a$33e23030$9ba69090$@samsung.com> > On 10/13/25 1:20 AM, Wonkon Kim wrote: > >> On 10/2/25 12:00 AM, Wonkon Kim wrote: > >>> static bool ufshcd_is_pwr_mode_restore_needed(struct ufs_hba *hba) > >>> { > >>> struct ufs_pa_layer_attr *pwr_info = &hba->pwr_info; > >>> - u32 mode; > >>> + u32 mode = 0; > >>> > >>> ufshcd_dme_get(hba, UIC_ARG_MIB(PA_PWRMODE), &mode); > >> > >> Since there is more code that passes a pointer to an uninitialized > >> variable to ufshcd_dme_get(), the untested patch below may be a > >> better > >> solution: > >> > >> diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c > >> index 127b691402f9..5226fbca29ec 100644 > >> --- a/drivers/ufs/core/ufshcd.c > >> +++ b/drivers/ufs/core/ufshcd.c > >> @@ -4277,8 +4277,8 @@ int ufshcd_dme_get_attr(struct ufs_hba *hba, > >> u32 attr_sel, > >> get, UIC_GET_ATTR_ID(attr_sel), > >> UFS_UIC_COMMAND_RETRIES - retries); > >> > >> - if (mib_val && !ret) > >> - *mib_val = uic_cmd.argument3; > >> + if (mib_val) > >> + *mib_val = ret == 0 ? uic_cmd.argument3 : 0; > >> > >> if (peer && (hba->quirks & UFSHCD_QUIRK_DME_PEER_ACCESS_AUTO_MODE) > >> && pwr_mode_change) > >> > >> > > > > There are some attributes to use 0 as valid value. > > e.g. PA_MAXRXHSGEAR is set to 0 for NO_HS=0 If it has 0 for valid > > value, most of value 0 are regarded as FALSE, unsupported or minimum. > > And these cases seems to check ret for command success/fail in code. > > However, is it ok to set 0 for ufshcd_send_uic_cmd() fail? > > > > If it can't, it needs to initialize mode. > > Value 0 for PA_PWRMODE is invalid. > > Hi Wonkon, > > Modifying ufshcd_dme_get_attr() doesn't exclude checking the return value > of ufshcd_dme_get_attr(). I propose to modify > ufshcd_dme_get_attr() such that it always initializes *mib_val and also to > check the ufshcd_dme_get_attr() return value wherever appropriate. > > Thanks, > > Bart. Hi Bart, I got it. I'll update it. Thanks, Wonkon Kim.