mfd: rtsx: Fix oops when rtsx_pci_sdmmc is not probed

If rtsx_pci_sdmmc is not probed, function pointer pcr->slots[].card_event
will point to NULL, and thus rtsx_pci_card_detect will reference a NULL
pointer.
Check card_event pointer before referencing it can avoid kernel panic.

Signed-off-by: Wei WANG <wei_wang@realsil.com.cn>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/mfd/rtsx_pcr.c b/drivers/mfd/rtsx_pcr.c
index 910200e10fa0..9fc57009e228 100644
--- a/drivers/mfd/rtsx_pcr.c
+++ b/drivers/mfd/rtsx_pcr.c
@@ -786,10 +786,10 @@ static void rtsx_pci_card_detect(struct work_struct *work)
 
         spin_unlock_irqrestore(&pcr->lock, flags);
 
-        if (card_detect & SD_EXIST)
+        if ((card_detect & SD_EXIST) && pcr->slots[RTSX_SD_CARD].card_event)
                 pcr->slots[RTSX_SD_CARD].card_event(
                                 pcr->slots[RTSX_SD_CARD].p_dev);
-        if (card_detect & MS_EXIST)
+        if ((card_detect & MS_EXIST) && pcr->slots[RTSX_MS_CARD].card_event)
                 pcr->slots[RTSX_MS_CARD].card_event(
                                 pcr->slots[RTSX_MS_CARD].p_dev);
 }