From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Hunter Subject: Re: [PATCH v2 3/3] mmc: sdhci-pci: only install voltage switch method when useful Date: Mon, 19 Nov 2018 09:45:03 +0200 Message-ID: <94fa0484-c532-683f-3a3f-fd9f4b263d16@intel.com> References: <20181022134026.GB18413@jaya> <20181023100729.28864-4-anisse@astier.eu> <20181116165850.GB5894@jaya> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20181116165850.GB5894@jaya> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Anisse Astier Cc: Ulf Hansson , linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-mmc@vger.kernel.org On 16/11/18 6:58 PM, Anisse Astier wrote: > Hi Adrian, > > On Tue, Oct 23, 2018 at 12:07:29PM +0200, Anisse Astier wrote: >> If there's no ACPI DSM for voltage switch, it will just cause a lot of >> debug info down the line, we only need one at startup. >> >> Signed-off-by: Anisse Astier >> --- >> drivers/mmc/host/sdhci-pci-core.c | 11 +++++++++++ >> 1 file changed, 11 insertions(+) >> >> diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c >> index f2c1fb339d66..95fdbb883c7e 100644 >> --- a/drivers/mmc/host/sdhci-pci-core.c >> +++ b/drivers/mmc/host/sdhci-pci-core.c >> @@ -723,6 +723,7 @@ static const struct dmi_system_id board_no_1_8v[] = { >> static void byt_probe_slot(struct sdhci_pci_slot *slot) >> { >> struct mmc_host_ops *ops = &slot->host->mmc_host_ops; >> + struct intel_host *intel_host = sdhci_pci_priv(slot); >> >> byt_read_dsm(slot); >> >> @@ -733,6 +734,16 @@ static void byt_probe_slot(struct sdhci_pci_slot *slot) >> mmc_hostname(slot->host->mmc)); >> slot->host->quirks2 |= SDHCI_QUIRK2_NO_1_8_V; >> } >> + /* Check if we have the appropriate voltage switch DSM methods */ >> + if (!(intel_host->dsm_fns & (1 << INTEL_DSM_V18_SWITCH)) && >> + !(intel_host->dsm_fns & (1 << INTEL_DSM_V33_SWITCH))) { >> + /* No voltage switching supported at all, there's no >> + * point in installing the callback: return. >> + */ >> + pr_debug("%s: No voltage switching ACPI DSM helper\n", >> + mmc_hostname(slot->host->mmc)); >> + return; >> + } >> ops->start_signal_voltage_switch = intel_start_signal_voltage_switch; >> } >> >> -- >> 2.17.2 >> > > What do you think of picking this last patch ? Or maybe you had > different cleanups in mind when you said you wanted to rework this ? Voltage switches are relatively rare, and dynamic debug allows control over exactly which debug messages display, so I am not sure this patch is needed.