Re: [PATCH] mmc: dw_mmc: rockchip: Keep controller working for card detect
From: Heiko Stübner <heiko@sntech.de>
Date: 2024-09-14 11:52:42
Also in:
linux-mmc, linux-rockchip, lkml
Am Donnerstag, 12. September 2024, 09:26:14 CEST schrieb Kever Yang:
In order to make the SD card hotplug working we need the card detect function logic inside the controller always working. The runtime PM will gate the clock and the power domain, which stops controller working when no data transfer happen. So lets skip enable runtime PM when the card needs to detected by the controller and the card is removable. Signed-off-by: Kever Yang <redacted>
So for the change itself this looks good, i.e. it fixes an issue for baords relying on the on-chip-card-detect. But for boards doing that, the controller will be running _all the time_ even if there is never any card inserted. So relying on the on-soc card-detect will effectively increase the power- consumption of the board - even it it'll never use any sd-card?
quoted hunk ↗ jump to hunk
--- drivers/mmc/host/dw_mmc-rockchip.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-)diff --git a/drivers/mmc/host/dw_mmc-rockchip.c b/drivers/mmc/host/dw_mmc-rockchip.c index b07190ba4b7a..df91205f9cd3 100644 --- a/drivers/mmc/host/dw_mmc-rockchip.c +++ b/drivers/mmc/host/dw_mmc-rockchip.c@@ -345,28 +345,39 @@ static int dw_mci_rockchip_probe(struct platform_device *pdev) const struct dw_mci_drv_data *drv_data; const struct of_device_id *match; int ret; + bool use_rpm = true; if (!pdev->dev.of_node) return -ENODEV; + if (!device_property_read_bool(&pdev->dev, "non-removable") &&
It would be nice to add a comment here about the fact that this will disable power-management for the controller. Also shouldn't non-removable already work, making the case above not necessary? Thanks Heiko
+ !device_property_read_bool(&pdev->dev, "cd-gpios"))
+ use_rpm = false;
+
match = of_match_node(dw_mci_rockchip_match, pdev->dev.of_node);
drv_data = match->data;
pm_runtime_get_noresume(&pdev->dev);
pm_runtime_set_active(&pdev->dev);
- pm_runtime_enable(&pdev->dev);
- pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
- pm_runtime_use_autosuspend(&pdev->dev);
+
+ if (use_rpm) {
+ pm_runtime_enable(&pdev->dev);
+ pm_runtime_set_autosuspend_delay(&pdev->dev, 50);
+ pm_runtime_use_autosuspend(&pdev->dev);
+ }
ret = dw_mci_pltfm_register(pdev, drv_data);
if (ret) {
- pm_runtime_disable(&pdev->dev);
- pm_runtime_set_suspended(&pdev->dev);
+ if (use_rpm) {
+ pm_runtime_disable(&pdev->dev);
+ pm_runtime_set_suspended(&pdev->dev);
+ }
pm_runtime_put_noidle(&pdev->dev);
return ret;
}
- pm_runtime_put_autosuspend(&pdev->dev);
+ if (use_rpm)
+ pm_runtime_put_autosuspend(&pdev->dev);
return 0;
}