mmc: sdhci-pci: why no .shutdown() implemented

From: Mansoor, Illyas
Date: Mon Mar 12 2012 - 04:15:54 EST


Hi All,

I'm not sure if this is the right mailing list to discuss this question, but
anyways I'll ask:

On our platform we implemented a BUG in pci_set_power_state callback when the
shutdown
Is in progress, and we caught sdci-pci doing pci_set_power_state(D0) when
shutdown was
Already in progress.

My question, why doesn't sdhci-pci.c implement a .shutdown() callback and close
the device
After doing sys_sync()?

Is there some reason behind it not doing a graceful shutdown.

I think it could cause corruption, since there is no guarantee when the system
will power-off/reboot/halt

I just implemented a patch to fix this, if it's a good fix I'll submit.

diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c
index f5fe05c..e0818c9 100644
--- a/drivers/mmc/host/sdhci-pci.c
+++ b/drivers/mmc/host/sdhci-pci.c
@@ -23,6 +23,7 @@
#include <linux/regulator/consumer.h>
#include <linux/pm_runtime.h>
#include <linux/async.h>
+#include <linux/syscalls.h>

#include <asm/scatterlist.h>
#include <asm/io.h>
@@ -1342,6 +1343,34 @@ err:
return ret;
}

+static void sdhci_pci_shutdown(struct pci_dev *pdev)
+{
+ int i;
+ struct sdhci_pci_chip *chip;
+
+ printk(KERN_INFO "%s: Syncing filesystems ... ", __func__);
+ sys_sync();
+ printk("done.\n");
+
+ pm_runtime_get_sync(&pdev->dev);
+
+ chip = pci_get_drvdata(pdev);
+
+ if (chip) {
+ for (i = 0;i < chip->num_slots; i++)
+ sdhci_pci_remove_slot(chip->slots[i]);
+
+ pci_set_drvdata(pdev, NULL);
+ kfree(chip);
+ }
+
+ pci_disable_device(pdev);
+
+ pm_runtime_put_noidle(&pdev->dev);
+ pm_runtime_forbid(&pdev->dev);
+ pm_runtime_disable(&pdev->dev);
+}
+
static void __devexit sdhci_pci_remove(struct pci_dev *pdev)
{
int i;
@@ -1473,6 +1502,7 @@ static struct pci_driver sdhci_driver = {
.id_table = pci_ids,
.probe = sdhci_pci_probe,
.remove = __devexit_p(sdhci_pci_remove),
+ .shutdown = sdhci_pci_shutdown,


-Illyas

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