[PATCH] MFD:rtsx:Avoid kernel panic if rtsx_pci_sdmmc not probed

[wei_wang]

From: Wei WANG <wei_wang@xxxxxxxxxxxxxx>

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@xxxxxxxxxxxxxx>
---
 drivers/mfd/rtsx_pcr.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mfd/rtsx_pcr.c b/drivers/mfd/rtsx_pcr.c
index 910200e..9fc5700 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);
 }
-- 
1.7.9.5

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