Revert "mmc: sdhci: Disable SD card clock before changing parameters"

It has turned out the trying to strictly conform to the SDHCI specification
is causing problems. Let's revert and start over.

This reverts commit fb3bbc4.

Cc: Erick Shepherd <[email protected]>
Cc: [email protected]
Fixes: fb3bbc4 ("mmc: sdhci: Disable SD card clock before changing parameters")
Suggested-by: Adrian Hunter <[email protected]>
Reported-by: Jonathan Liu <[email protected]>
Reported-by: Salvatore Bonaccorso <[email protected]>
Closes: https://bugs.debian.org/1108065
Acked-by: Adrian Hunter <[email protected]>
Signed-off-by: Ulf Hansson <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: storulf

drivers/mmc/host/sdhci.c

@@ -2065,15 +2065,10 @@ void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
 
 	host->mmc->actual_clock = 0;
 
-	clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
-	if (clk & SDHCI_CLOCK_CARD_EN)
-		sdhci_writew(host, clk & ~SDHCI_CLOCK_CARD_EN,
-			SDHCI_CLOCK_CONTROL);
+	sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
 
-	if (clock == 0) {
-		sdhci_writew(host, 0, SDHCI_CLOCK_CONTROL);
+	if (clock == 0)
 		return;
-	}
 
 	clk = sdhci_calc_clk(host, clock, &host->mmc->actual_clock);
 	sdhci_enable_clk(host, clk);