lkml.org 
[lkml]   [2021]   [Dec]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/5] mmc: mtk-sd: Use readl_poll_timeout instead of open-coded polling
Date
Replace all instances of open-coded while loops for polling registers
with calls to readl_poll_timeout() and, while at it, also fix some
possible infinite loop instances.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
---
drivers/mmc/host/mtk-sd.c | 64 ++++++++++++++++++++++++---------------
1 file changed, 39 insertions(+), 25 deletions(-)

diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c
index 632775217d35..d5a9c269d492 100644
--- a/drivers/mmc/host/mtk-sd.c
+++ b/drivers/mmc/host/mtk-sd.c
@@ -636,12 +636,11 @@ static void msdc_reset_hw(struct msdc_host *host)
u32 val;

sdr_set_bits(host->base + MSDC_CFG, MSDC_CFG_RST);
- while (readl(host->base + MSDC_CFG) & MSDC_CFG_RST)
- cpu_relax();
+ readl_poll_timeout(host->base + MSDC_CFG, val, !(val & MSDC_CFG_RST), 0, 0);

sdr_set_bits(host->base + MSDC_FIFOCS, MSDC_FIFOCS_CLR);
- while (readl(host->base + MSDC_FIFOCS) & MSDC_FIFOCS_CLR)
- cpu_relax();
+ readl_poll_timeout(host->base + MSDC_FIFOCS, val,
+ !(val & MSDC_FIFOCS_CLR), 0, 0);

val = readl(host->base + MSDC_INT);
writel(val, host->base + MSDC_INT);
@@ -814,8 +813,9 @@ static void msdc_gate_clock(struct msdc_host *host)
clk_disable_unprepare(host->h_clk);
}

-static void msdc_ungate_clock(struct msdc_host *host)
+static int msdc_ungate_clock(struct msdc_host *host)
{
+ u32 val;
int ret;

clk_prepare_enable(host->h_clk);
@@ -825,11 +825,11 @@ static void msdc_ungate_clock(struct msdc_host *host)
ret = clk_bulk_prepare_enable(MSDC_NR_CLOCKS, host->bulk_clks);
if (ret) {
dev_err(host->dev, "Cannot enable pclk/axi/ahb clock gates\n");
- return;
+ return ret;
}

- while (!(readl(host->base + MSDC_CFG) & MSDC_CFG_CKSTB))
- cpu_relax();
+ return readl_poll_timeout(host->base + MSDC_CFG, val,
+ (val & MSDC_CFG_CKSTB), 1, 20000);
}

static void msdc_set_mclk(struct msdc_host *host, unsigned char timing, u32 hz)
@@ -840,6 +840,7 @@ static void msdc_set_mclk(struct msdc_host *host, unsigned char timing, u32 hz)
u32 div;
u32 sclk;
u32 tune_reg = host->dev_comp->pad_tune_reg;
+ u32 val;

if (!hz) {
dev_dbg(host->dev, "set mclk to 0\n");
@@ -920,8 +921,7 @@ static void msdc_set_mclk(struct msdc_host *host, unsigned char timing, u32 hz)
else
clk_prepare_enable(clk_get_parent(host->src_clk));

- while (!(readl(host->base + MSDC_CFG) & MSDC_CFG_CKSTB))
- cpu_relax();
+ readl_poll_timeout(host->base + MSDC_CFG, val, (val & MSDC_CFG_CKSTB), 0, 0);
sdr_set_bits(host->base + MSDC_CFG, MSDC_CFG_CKPDN);
mmc->actual_clock = sclk;
host->mclk = hz;
@@ -1231,13 +1231,13 @@ static bool msdc_cmd_done(struct msdc_host *host, int events,
static inline bool msdc_cmd_is_ready(struct msdc_host *host,
struct mmc_request *mrq, struct mmc_command *cmd)
{
- /* The max busy time we can endure is 20ms */
- unsigned long tmo = jiffies + msecs_to_jiffies(20);
+ u32 val;
+ int ret;

- while ((readl(host->base + SDC_STS) & SDC_STS_CMDBUSY) &&
- time_before(jiffies, tmo))
- cpu_relax();
- if (readl(host->base + SDC_STS) & SDC_STS_CMDBUSY) {
+ /* The max busy time we can endure is 20ms */
+ ret = readl_poll_timeout_atomic(host->base + SDC_STS, val,
+ !(val & SDC_STS_CMDBUSY), 1, 20000);
+ if (ret) {
dev_err(host->dev, "CMD bus busy detected\n");
host->error |= REQ_CMD_BUSY;
msdc_cmd_done(host, MSDC_INT_CMDTMO, mrq, cmd);
@@ -1245,12 +1245,10 @@ static inline bool msdc_cmd_is_ready(struct msdc_host *host,
}

if (mmc_resp_type(cmd) == MMC_RSP_R1B || cmd->data) {
- tmo = jiffies + msecs_to_jiffies(20);
/* R1B or with data, should check SDCBUSY */
- while ((readl(host->base + SDC_STS) & SDC_STS_SDCBUSY) &&
- time_before(jiffies, tmo))
- cpu_relax();
- if (readl(host->base + SDC_STS) & SDC_STS_SDCBUSY) {
+ ret = readl_poll_timeout_atomic(host->base + SDC_STS, val,
+ !(val & SDC_STS_SDCBUSY), 1, 20000);
+ if (ret) {
dev_err(host->dev, "Controller busy detected\n");
host->error |= REQ_CMD_BUSY;
msdc_cmd_done(host, MSDC_INT_CMDTMO, mrq, cmd);
@@ -1376,6 +1374,8 @@ static bool msdc_data_xfer_done(struct msdc_host *host, u32 events,
(MSDC_INT_XFER_COMPL | MSDC_INT_DATCRCERR | MSDC_INT_DATTMO
| MSDC_INT_DMA_BDCSERR | MSDC_INT_DMA_GPDCSERR
| MSDC_INT_DMA_PROTECT);
+ u32 val;
+ int ret;

spin_lock_irqsave(&host->lock, flags);
done = !host->data;
@@ -1392,8 +1392,14 @@ static bool msdc_data_xfer_done(struct msdc_host *host, u32 events,
readl(host->base + MSDC_DMA_CFG));
sdr_set_field(host->base + MSDC_DMA_CTRL, MSDC_DMA_CTRL_STOP,
1);
- while (readl(host->base + MSDC_DMA_CFG) & MSDC_DMA_CFG_STS)
- cpu_relax();
+
+ ret = readl_poll_timeout_atomic(host->base + MSDC_DMA_CFG, val,
+ !(val & MSDC_DMA_CFG_STS), 1, 20000);
+ if (ret) {
+ dev_dbg(host->dev, "DMA stop timed out\n");
+ return false;
+ }
+
sdr_clr_bits(host->base + MSDC_INTEN, data_ints_mask);
dev_dbg(host->dev, "DMA stop\n");

@@ -2674,7 +2680,11 @@ static int msdc_drv_probe(struct platform_device *pdev)
spin_lock_init(&host->lock);

platform_set_drvdata(pdev, mmc);
- msdc_ungate_clock(host);
+ ret = msdc_ungate_clock(host);
+ if (ret) {
+ dev_err(&pdev->dev, "Cannot ungate clocks!\n");
+ goto release_mem;
+ }
msdc_init_hw(host);

if (mmc->caps2 & MMC_CAP2_CQE) {
@@ -2833,8 +2843,12 @@ static int __maybe_unused msdc_runtime_resume(struct device *dev)
{
struct mmc_host *mmc = dev_get_drvdata(dev);
struct msdc_host *host = mmc_priv(mmc);
+ int ret;
+
+ ret = msdc_ungate_clock(host);
+ if (ret)
+ return ret;

- msdc_ungate_clock(host);
msdc_restore_reg(host);
return 0;
}
--
2.33.1
\
 
 \ /
  Last update: 2021-12-16 13:58    [W:0.094 / U:0.180 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site