mmc: omap_hsmmc: Fix Oops in case of data errors

ae4bf788ee9 ("mmc: omap_hsmmc: consolidate error report handling of HSMMC
IRQ") sets both end_cmd and end_trans to 1.

Setting end_cmd to 1 for Data Timeout/CRC leads to NULL pointer dereference of
host->cmd as the command complete has previously been handled.
Set end_cmd only in case of command Timeout/CRC.

Moreover host->cmd->error should not be updated on data error case, only
host->data->error needs to be updated.

Signed-off-by: Balaji T K <balajitk@ti.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Venkatraman S <svenkatr@ti.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/omap_hsmmc.c

@@ -969,10 +969,14 @@ static inline void omap_hsmmc_reset_controller_fsm(struct omap_hsmmc_host *host,
 			__func__);
 }
 
-static void hsmmc_command_incomplete(struct omap_hsmmc_host *host, int err)
+static void hsmmc_command_incomplete(struct omap_hsmmc_host *host,
+					int err, int end_cmd)
 {
 	omap_hsmmc_reset_controller_fsm(host, SRC);
-	host->cmd->error = err;
+	if (end_cmd) {
+		if (host->cmd)
+			host->cmd->error = err;
+	}
 
 	if (host->data) {
 		omap_hsmmc_reset_controller_fsm(host, SRD);
@@ -991,14 +995,16 @@ static void omap_hsmmc_do_irq(struct omap_hsmmc_host *host, int status)
 
 	if (status & ERR) {
 		omap_hsmmc_dbg_report_irq(host, status);
+
+		if (status & (CMD_TIMEOUT | CMD_CRC))
+			end_cmd = 1;
 		if (status & (CMD_TIMEOUT | DATA_TIMEOUT))
-			hsmmc_command_incomplete(host, -ETIMEDOUT);
+			hsmmc_command_incomplete(host, -ETIMEDOUT, end_cmd);
 		else if (status & (CMD_CRC | DATA_CRC))
-			hsmmc_command_incomplete(host, -EILSEQ);
+			hsmmc_command_incomplete(host, -EILSEQ, end_cmd);
 
-		end_cmd = 1;
 		if (host->data || host->response_busy) {
-			end_trans = 1;
+			end_trans = !end_cmd;
 			host->response_busy = 0;
 		}
 	}