drivers/card_reader/rtsx_usb: Restore interrupt based detection

This commit reintroduces interrupt-based card detection previously
used in the rts5139 driver. This functionality was removed in commit
00d8521dcd23 ("staging: remove rts5139 driver code").

Reintroducing this mechanism fixes presence detection for certain card
readers, which with the current driver, will taken approximately 20
seconds to enter S3 as `mmc_rescan` has to be frozen.

Fixes: 00d8521dcd23 ("staging: remove rts5139 driver code")
Cc: stable@vger.kernel.org
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sean Rhodes <sean@starlabs.systems>
Link: https://lore.kernel.org/r/20241119085815.11769-1-sean@starlabs.systems
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/misc/cardreader/rtsx_usb.c b/drivers/misc/cardreader/rtsx_usb.c
index 77b0490a1b38d79134d48020bd49a9fa6f0df967..e0174da5e9fc39ae96b70ce70d57a87dfaa2ebdb 100644 (file)
--- a/drivers/misc/cardreader/rtsx_usb.c
+++ b/drivers/misc/cardreader/rtsx_usb.c
@@ -286,6 +286,7 @@ static int rtsx_usb_get_status_with_bulk(struct rtsx_ucr *ucr, u16 *status)
 int rtsx_usb_get_card_status(struct rtsx_ucr *ucr, u16 *status)
 {
        int ret;
+       u8 interrupt_val = 0;
        u16 *buf;
 
        if (!status)
@@ -308,6 +309,20 @@ int rtsx_usb_get_card_status(struct rtsx_ucr *ucr, u16 *status)
                ret = rtsx_usb_get_status_with_bulk(ucr, status);
        }
 
+       rtsx_usb_read_register(ucr, CARD_INT_PEND, &interrupt_val);
+       /* Cross check presence with interrupts */
+       if (*status & XD_CD)
+               if (!(interrupt_val & XD_INT))
+                       *status &= ~XD_CD;
+
+       if (*status & SD_CD)
+               if (!(interrupt_val & SD_INT))
+                       *status &= ~SD_CD;
+
+       if (*status & MS_CD)
+               if (!(interrupt_val & MS_INT))
+                       *status &= ~MS_CD;
+
        /* usb_control_msg may return positive when success */
        if (ret < 0)
                return ret;