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| author | Théo Lebrun <theo.lebrun@bootlin.com> | 2024-04-23 12:01:42 +0200 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2024-04-26 11:09:24 +0900 |
| commit | c1887396373b8faecef61d352bd521ac66162706 (patch) | |
| tree | 8a533995239bf7bedbcf8722857ca0fec27a445a /drivers/spi/spi-cadence-quadspi.c | |
| parent | 1f257b92e6330d576cc826fb8f0b74fe0e8209de (diff) | |
| download | lwn-c1887396373b8faecef61d352bd521ac66162706.tar.gz lwn-c1887396373b8faecef61d352bd521ac66162706.zip | |
spi: cadence-qspi: add early busywait to cqspi_wait_for_bit()
Call readl_relaxed_poll_timeout() with no sleep at the start of
cqspi_wait_for_bit(). If its short timeout expires, a sleeping
readl_relaxed_poll_timeout() call takes the relay.
The reason is to avoid hrtimer interrupts on the system. All read
operations are expected to take less than 100µs.
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
Link: https://lore.kernel.org/r/20240423-cdns-qspi-mbly-v4-3-3d2a7b535ad0@bootlin.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi/spi-cadence-quadspi.c')
| -rw-r--r-- | drivers/spi/spi-cadence-quadspi.c | 31 |
1 files changed, 23 insertions, 8 deletions
diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c index a82e23526a6f..87c88ee708e4 100644 --- a/drivers/spi/spi-cadence-quadspi.c +++ b/drivers/spi/spi-cadence-quadspi.c @@ -120,6 +120,7 @@ struct cqspi_driver_platdata { /* Operation timeout value */ #define CQSPI_TIMEOUT_MS 500 #define CQSPI_READ_TIMEOUT_MS 10 +#define CQSPI_BUSYWAIT_TIMEOUT_US 500 /* Runtime_pm autosuspend delay */ #define CQSPI_AUTOSUSPEND_TIMEOUT 2000 @@ -298,13 +299,27 @@ struct cqspi_driver_platdata { #define CQSPI_REG_VERSAL_DMA_VAL 0x602 -static int cqspi_wait_for_bit(void __iomem *reg, const u32 mask, bool clr) +static int cqspi_wait_for_bit(const struct cqspi_driver_platdata *ddata, + void __iomem *reg, const u32 mask, bool clr, + bool busywait) { + u64 timeout_us = CQSPI_TIMEOUT_MS * USEC_PER_MSEC; u32 val; + if (busywait) { + int ret = readl_relaxed_poll_timeout(reg, val, + (((clr ? ~val : val) & mask) == mask), + 0, CQSPI_BUSYWAIT_TIMEOUT_US); + + if (ret != -ETIMEDOUT) + return ret; + + timeout_us -= CQSPI_BUSYWAIT_TIMEOUT_US; + } + return readl_relaxed_poll_timeout(reg, val, (((clr ? ~val : val) & mask) == mask), - 10, CQSPI_TIMEOUT_MS * 1000); + 10, timeout_us); } static bool cqspi_is_idle(struct cqspi_st *cqspi) @@ -434,8 +449,8 @@ static int cqspi_exec_flash_cmd(struct cqspi_st *cqspi, unsigned int reg) writel(reg, reg_base + CQSPI_REG_CMDCTRL); /* Polling for completion. */ - ret = cqspi_wait_for_bit(reg_base + CQSPI_REG_CMDCTRL, - CQSPI_REG_CMDCTRL_INPROGRESS_MASK, 1); + ret = cqspi_wait_for_bit(cqspi->ddata, reg_base + CQSPI_REG_CMDCTRL, + CQSPI_REG_CMDCTRL_INPROGRESS_MASK, 1, true); if (ret) { dev_err(&cqspi->pdev->dev, "Flash command execution timed out.\n"); @@ -790,8 +805,8 @@ static int cqspi_indirect_read_execute(struct cqspi_flash_pdata *f_pdata, } /* Check indirect done status */ - ret = cqspi_wait_for_bit(reg_base + CQSPI_REG_INDIRECTRD, - CQSPI_REG_INDIRECTRD_DONE_MASK, 0); + ret = cqspi_wait_for_bit(cqspi->ddata, reg_base + CQSPI_REG_INDIRECTRD, + CQSPI_REG_INDIRECTRD_DONE_MASK, 0, true); if (ret) { dev_err(dev, "Indirect read completion error (%i)\n", ret); goto failrd; @@ -1091,8 +1106,8 @@ static int cqspi_indirect_write_execute(struct cqspi_flash_pdata *f_pdata, } /* Check indirect done status */ - ret = cqspi_wait_for_bit(reg_base + CQSPI_REG_INDIRECTWR, - CQSPI_REG_INDIRECTWR_DONE_MASK, 0); + ret = cqspi_wait_for_bit(cqspi->ddata, reg_base + CQSPI_REG_INDIRECTWR, + CQSPI_REG_INDIRECTWR_DONE_MASK, 0, false); if (ret) { dev_err(dev, "Indirect write completion error (%i)\n", ret); goto failwr; |