From: Haibo Chen <haibo.chen@nxp.com>
Date: Fri, 13 Aug 2021 20:34:01 +0800
Subject: mmc: sdhci: Correct the tuning command handle for PIO mode

Git-commit: f4ff24f8a7c144e6d2107a2f2d16bcd9e2b2578f
Patch-mainline: v5.15-rc1
References: jsc#SLE-19033

If sdhci use PIO mode, and use mmc_send_tuning() to send the tuning
command, system will stuck because of the storm irq of sdhci. For PIO mode,
use mmc_send_tuning(), it will trigger buffer_read_ready interrupt and data
transfer complete interrupt.  In current code logic, it will directly
return in sdhci_data_irq, can not call the sdhci_transfer_pio(). So the
buffer_read_ready interrupt storm happen. So for standard tuning method,
need to exclude this case.

Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/1628858041-1911-1-git-send-email-haibo.chen@nxp.com
[Ulf: Dropped redundant parenthesis in an expression]
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Mian Yousaf Kaukab <ykaukab@suse.de>
---
 drivers/mmc/host/sdhci.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 36f15f81a6af..8eefa7d5fe85 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -3279,8 +3279,14 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
 {
 	u32 command;
 
-	/* CMD19 generates _only_ Buffer Read Ready interrupt */
-	if (intmask & SDHCI_INT_DATA_AVAIL) {
+	/*
+	 * CMD19 generates _only_ Buffer Read Ready interrupt if
+	 * use sdhci_send_tuning.
+	 * Need to exclude this case: PIO mode and use mmc_send_tuning,
+	 * If not, sdhci_transfer_pio will never be called, make the
+	 * SDHCI_INT_DATA_AVAIL always there, stuck in irq storm.
+	 */
+	if (intmask & SDHCI_INT_DATA_AVAIL && !host->data) {
 		command = SDHCI_GET_CMD(sdhci_readw(host, SDHCI_COMMAND));
 		if (command == MMC_SEND_TUNING_BLOCK ||
 		    command == MMC_SEND_TUNING_BLOCK_HS200) {
-- 
2.31.1