[PATCH 5.15 018/917] mmc: mtk-sd: Add wait dma stop done flow

Greg Kroah-Hartman
2021-11-16T01:12:24Z

From: Derong Liu <derong.liu@mediatek.com>

commit 43e5fee317f4b0a48992b8b07935b1a3ac20ce84 upstream.

We found this issue on a 5G platform, during CMDQ error handling, if DMA
status is active when it call msdc_reset_hw(), it means mmc host hw reset
and DMA transfer will be parallel, mmc host may access sram region
unexpectedly. According to the programming guide of mtk-sd host, it needs
to wait for dma stop done after set dma stop.

This change should be applied to all SoCs.

Signed-off-by: Derong Liu <derong.liu@mediatek.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20210827071537.1034-1-derong.liu@mediatek.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/mmc/host/mtk-sd.c | 5 +++++
1 file changed, 5 insertions(+)

--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -8,6 +8,7 @@
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
+#include <linux/iopoll.h>
#include <linux/ioport.h>
#include <linux/irq.h>
#include <linux/of_address.h>
@@ -2330,6 +2331,7 @@ static void msdc_cqe_enable(struct mmc_h
static void msdc_cqe_disable(struct mmc_host *mmc, bool recovery)
{
struct msdc_host *host = mmc_priv(mmc);
+ unsigned int val = 0;

/* disable cmdq irq */
sdr_clr_bits(host->base + MSDC_INTEN, MSDC_INT_CMDQ);
@@ -2339,6 +2341,9 @@ static void msdc_cqe_disable(struct mmc_
if (recovery) {
sdr_set_field(host->base + MSDC_DMA_CTRL,
MSDC_DMA_CTRL_STOP, 1);
+ if (WARN_ON(readl_poll_timeout(host->base + MSDC_DMA_CFG, val,
+ !(val & MSDC_DMA_CFG_STS), 1, 3000)))
+ return;
msdc_reset_hw(host);
}
}