From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vivek Gautam Subject: Re: [PATCH v5 1/6] base: power: runtime: Export pm_runtime_get/put_suppliers Date: Fri, 12 Jan 2018 11:17:33 +0530 Message-ID: <65d04510-bd88-7afe-27b5-d5e9cb416949@codeaurora.org> References: <1515492109-753-1-git-send-email-vivek.gautam@codeaurora.org> <1515492109-753-2-git-send-email-vivek.gautam@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: iommu-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: "Rafael J. Wysocki" Cc: Mark Rutland , Len Brown , David Airlie , Stephen Boyd , Will Deacon , dri-devel , Pavel Machek , "devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Linux PM , linux-arm-msm , Rob Herring , freedreno-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, Greg Kroah-Hartman , "Rafael J. Wysocki" , Linux Kernel Mailing List , "open list:AMD IOMMU (AMD-VI)" List-Id: devicetree@vger.kernel.org On 01/12/2018 04:23 AM, Rafael J. Wysocki wrote: > On Tue, Jan 9, 2018 at 11:01 AM, Vivek Gautam > wrote: >> The device link allows the pm framework to tie the supplier and >> consumer. So, whenever the consumer is powered-on the supplier >> is powered-on first. >> >> There are however cases in which the consumer wants to power-on >> the supplier, but not itself. >> E.g., A Graphics or multimedia driver wants to power-on the SMMU >> to unmap a buffer and finish the TLB operations without powering >> on itself. Some of these unmap requests are coming from the >> user space when the controller itself is not powered-up, and it >> can be huge penalty in terms of power and latency to power-up >> the graphics/mm controllers. >> There can be an argument that the supplier should handle this case >> on its own and there should not be a need for the consumer to >> power-on the supplier. But as discussed on the thread [1] about >> ARM-SMMU runtime pm, we don't want to introduce runtime pm calls >> in atomic path in arm_smmu_unmap. >> >> [1] https://patchwork.kernel.org/patch/9827825/ >> >> Signed-off-by: Vivek Gautam > Acked-by: Rafael J. Wysocki > > Please feel free to route this along with the rest of the series. Thanks Rafael. regards Vivek > > Thanks! > >> --- >> >> * This is v2 of the patch [1]. Adding it to this patch series. >> [1] https://patchwork.kernel.org/patch/10102447/ >> >> drivers/base/power/runtime.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/drivers/base/power/runtime.c b/drivers/base/power/runtime.c >> index 6e89b51ea3d9..06a2a88fe866 100644 >> --- a/drivers/base/power/runtime.c >> +++ b/drivers/base/power/runtime.c >> @@ -1579,6 +1579,7 @@ void pm_runtime_get_suppliers(struct device *dev) >> >> device_links_read_unlock(idx); >> } >> +EXPORT_SYMBOL_GPL(pm_runtime_get_suppliers); >> >> /** >> * pm_runtime_put_suppliers - Drop references to supplier devices. >> @@ -1597,6 +1598,7 @@ void pm_runtime_put_suppliers(struct device *dev) >> >> device_links_read_unlock(idx); >> } >> +EXPORT_SYMBOL_GPL(pm_runtime_put_suppliers); >> >> void pm_runtime_new_link(struct device *dev) >> { >> -- >> QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member >> of Code Aurora Forum, hosted by The Linux Foundation >> > -- > To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- The Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project