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mmc: mtk-sd: Use readl_poll_timeout instead of open-coded polling
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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>
Link: https://lore.kernel.org/r/20211216125748.179602-1-angelogioacchino.delregno@collabora.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
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@storulf
AngeloGioacchino Del Regno authored and storulf committed Dec 28, 2021
1 parent 585cba9 commit ffaea6e
Showing 1 changed file with 39 additions and 25 deletions.
64 changes: 39 additions & 25 deletions drivers/mmc/host/mtk-sd.c
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Original file line number Diff line number Diff line change
Expand Up @@ -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);
Expand Down Expand Up @@ -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);
Expand All @@ -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)
Expand All @@ -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");
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -1231,26 +1231,24 @@ 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);
return false;
}

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);
Expand Down Expand Up @@ -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;
Expand All @@ -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");

Expand Down Expand Up @@ -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) {
Expand Down Expand Up @@ -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;
}
Expand Down

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