Re: [RESEND PATCH v5 2/2] mmc: sdhci-of-arasan: add phy support for sdhci-of-arasan

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Hi Adrian,

On 2016/3/4 20:12, Adrian Hunter wrote:

[...]


I don't know that disabling clocks is necessarily the right thing to do if
the resume fails.  You might want to consider what happens if the system
tries to use the device when it is in that state.  It's been a long time
since I did any ARM work but aren't you risking bus errors.  Might just as
well not bother and save a few lines of code.


Firstly, I really just follow the orginal err handle.
It's risking bus errors if disabling ahb clk, but ahb clk is most very
likely to shared by many controllers. So regarding to the clk reference
count, the ahb_clk is not *really* disabled and just decrease the
reference count. How about keep these handles here?

I would remove the error handling on the grounds that it does not do
anything useful.

Take another ronud of thinking it, probably you are right. When failing
to resume from deelp sleep, we return err to dpm. dpm still roll-forward
to wakeup by calling resume callback one-by-one. It means that finally
when system in wakeup state with disabled ahb_clk, but we then going to
access mmc as normal, which is not acceptable. Especially for debuging
the failure, we have to enable ahb_clk manually.

Will remove the error handling.

Thanks.




+    return ret;
   }
   #endif /* ! CONFIG_PM_SLEEP */

@@ -183,6 +207,30 @@ static int sdhci_arasan_probe(struct platform_device
*pdev)
           goto clk_disable_all;
       }

+    sdhci_arasan->phy = ERR_PTR(-ENODEV);
+    if (of_device_is_compatible(pdev->dev.of_node,
+                    "arasan,sdhci-5.1")) {
+        sdhci_arasan->phy = devm_phy_get(&pdev->dev,
+                         "phy_arasan");
+        if (IS_ERR(sdhci_arasan->phy)) {
+            ret = PTR_ERR(sdhci_arasan->phy);
+            dev_err(&pdev->dev, "No phy for arasan,sdhci-5.1.\n");
+            goto clk_disable_all;
+        }
+
+        ret = phy_init(sdhci_arasan->phy);
+        if (ret < 0) {
+            dev_err(&pdev->dev, "phy_init err.\n");
+            goto clk_disable_all;
+        }
+
+        ret = phy_power_on(sdhci_arasan->phy);
+        if (ret < 0) {
+            dev_err(&pdev->dev, "phy_power_on err.\n");
+            goto err_phy_power;
+        }
+    }
+
       ret = sdhci_add_host(host);
       if (ret)
           goto err_pltfm_free;
@@ -190,7 +238,12 @@ static int sdhci_arasan_probe(struct platform_device
*pdev)
       return 0;

   err_pltfm_free:
+    if (!IS_ERR(sdhci_arasan->phy))
+        phy_power_off(sdhci_arasan->phy);
       sdhci_pltfm_free(pdev);
+err_phy_power:
+    if (!IS_ERR(sdhci_arasan->phy))

Looks like you are using sdhci_arasan after it has been free'd by
sdhci_pltfm_free().

Also there seem to be cases where sdhci_arasan_probe() can exit after
sdhci_pltfm_init() without calling sdhci_pltfm_free().

Good catch, will fix it.


+        phy_exit(sdhci_arasan->phy);
   clk_disable_all:
       clk_disable_unprepare(clk_xin);
   clk_dis_ahb:
@@ -205,6 +258,11 @@ static int sdhci_arasan_remove(struct
platform_device *pdev)
       struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
       struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;

+    if (!IS_ERR(sdhci_arasan->phy)) {
+        phy_power_off(sdhci_arasan->phy);
+        phy_exit(sdhci_arasan->phy);
+    }
+

When you re-base, take care to keep this chunk above
sdhci_pltfm_unregister().

sure.

Thanks for reviewing it.


       clk_disable_unprepare(sdhci_arasan->clk_ahb);

       return sdhci_pltfm_unregister(pdev);













--
Best Regards
Shawn Lin

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