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Subject[PATCH 4.4 142/342] mmc: sdhci-pci: Fix card detect race for Intel BXT/APL
Date
4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Adrian Hunter <adrian.hunter@intel.com>

commit 163cbe31e5163459908a41a2b4e0d33a28fd557a upstream.

Intel BXT/APL use a card detect GPIO however the host controller
will not enable bus power unless it's card detect also reflects
the presence of a card. Unfortunately those 2 things race which
can result in commands not starting, after which the controller
does nothing and there is a 10 second wait for the driver's
10-second timer to timeout.

That is fixed by having the driver look also at the present state
register to determine if the card is present. Consequently, provide
a 'get_cd' mmc host operation for BXT/APL that does that.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/mmc/host/sdhci-pci-core.c | 31 +++++++++++++++++++++++++++++++
1 file changed, 31 insertions(+)

--- a/drivers/mmc/host/sdhci-pci-core.c
+++ b/drivers/mmc/host/sdhci-pci-core.c
@@ -330,6 +330,33 @@ static void spt_read_drive_strength(stru
sdhci_pci_spt_drive_strength = 0x10 | ((val >> 12) & 0xf);
}

+static int bxt_get_cd(struct mmc_host *mmc)
+{
+ int gpio_cd = mmc_gpio_get_cd(mmc);
+ struct sdhci_host *host = mmc_priv(mmc);
+ unsigned long flags;
+ int ret = 0;
+
+ if (!gpio_cd)
+ return 0;
+
+ pm_runtime_get_sync(mmc->parent);
+
+ spin_lock_irqsave(&host->lock, flags);
+
+ if (host->flags & SDHCI_DEVICE_DEAD)
+ goto out;
+
+ ret = !!(sdhci_readl(host, SDHCI_PRESENT_STATE) & SDHCI_CARD_PRESENT);
+out:
+ spin_unlock_irqrestore(&host->lock, flags);
+
+ pm_runtime_mark_last_busy(mmc->parent);
+ pm_runtime_put_autosuspend(mmc->parent);
+
+ return ret;
+}
+
static int byt_emmc_probe_slot(struct sdhci_pci_slot *slot)
{
slot->host->mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_NONREMOVABLE |
@@ -362,6 +389,10 @@ static int byt_sd_probe_slot(struct sdhc
slot->cd_con_id = NULL;
slot->cd_idx = 0;
slot->cd_override_level = true;
+ if (slot->chip->pdev->device == PCI_DEVICE_ID_INTEL_BXT_SD ||
+ slot->chip->pdev->device == PCI_DEVICE_ID_INTEL_APL_SD)
+ slot->host->mmc_host_ops.get_cd = bxt_get_cd;
+
return 0;
}
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