mmc: sdhci-pci: Fix initialization of some SD cards for Intel BYT-based controllers

Bus power may control card power, but the full reset done by SDHCI at
initialization still may not reset the power, whereas a direct write to
SDHCI_POWER_CONTROL can. That might be needed to initialize correctly, if
the card was left powered on previously.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210331081752.23621-1-adrian.hunter@intel.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/mmc/host/sdhci-pci-core.c b/drivers/mmc/host/sdhci-pci-core.c
index b3caa174effe1c1f6f4718f4cbb3a502ed24e12d..be19785227fe49af4882fa8fde1cc64454e86838 100644 (file)
--- a/drivers/mmc/host/sdhci-pci-core.c
+++ b/drivers/mmc/host/sdhci-pci-core.c
@@ -516,6 +516,7 @@ struct intel_host {
        int     drv_strength;
        bool    d3_retune;
        bool    rpm_retune_ok;
+       bool    needs_pwr_off;
        u32     glk_rx_ctrl1;
        u32     glk_tun_val;
        u32     active_ltr;
@@ -643,9 +644,25 @@ out:
 static void sdhci_intel_set_power(struct sdhci_host *host, unsigned char mode,
                                  unsigned short vdd)
 {
+       struct sdhci_pci_slot *slot = sdhci_priv(host);
+       struct intel_host *intel_host = sdhci_pci_priv(slot);
        int cntr;
        u8 reg;
 
+       /*
+        * Bus power may control card power, but a full reset still may not
+        * reset the power, whereas a direct write to SDHCI_POWER_CONTROL can.
+        * That might be needed to initialize correctly, if the card was left
+        * powered on previously.
+        */
+       if (intel_host->needs_pwr_off) {
+               intel_host->needs_pwr_off = false;
+               if (mode != MMC_POWER_OFF) {
+                       sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
+                       usleep_range(10000, 12500);
+               }
+       }
+
        sdhci_set_power(host, mode, vdd);
 
        if (mode == MMC_POWER_OFF)
@@ -1135,6 +1152,14 @@ static int byt_sdio_probe_slot(struct sdhci_pci_slot *slot)
        return 0;
 }
 
+static void byt_needs_pwr_off(struct sdhci_pci_slot *slot)
+{
+       struct intel_host *intel_host = sdhci_pci_priv(slot);
+       u8 reg = sdhci_readb(slot->host, SDHCI_POWER_CONTROL);
+
+       intel_host->needs_pwr_off = reg  & SDHCI_POWER_ON;
+}
+
 static int byt_sd_probe_slot(struct sdhci_pci_slot *slot)
 {
        byt_probe_slot(slot);
@@ -1152,6 +1177,8 @@ static int byt_sd_probe_slot(struct sdhci_pci_slot *slot)
            slot->chip->pdev->subsystem_device == PCI_SUBDEVICE_ID_NI_78E3)
                slot->host->mmc->caps2 |= MMC_CAP2_AVOID_3_3V;
 
+       byt_needs_pwr_off(slot);
+
        return 0;
 }