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| author | Eddie James <eajames@linux.ibm.com> | 2022-03-17 16:14:26 -0500 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2022-03-18 16:05:08 +0000 |
| commit | 89b35e3f28514087d3f1e28e8f5634fbfd07c554 (patch) | |
| tree | 40c27e02be84cfe185165eaa707f2339f5771325 /drivers/spi | |
| parent | ebc4cb43ea5ada3db46c80156fca58a54b9bbca8 (diff) | |
| download | linux-rpi-89b35e3f28514087d3f1e28e8f5634fbfd07c554.tar.gz linux-rpi-89b35e3f28514087d3f1e28e8f5634fbfd07c554.tar.bz2 linux-rpi-89b35e3f28514087d3f1e28e8f5634fbfd07c554.zip | |
spi: fsi: Implement a timeout for polling status
The data transfer routines must poll the status register to
determine when more data can be shifted in or out. If the hardware
gets into a bad state, these polling loops may never exit. Prevent
this by returning an error if a timeout is exceeded.
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Link: https://lore.kernel.org/r/20220317211426.38940-1-eajames@linux.ibm.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/spi-fsi.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/spi/spi-fsi.c b/drivers/spi/spi-fsi.c index b6c7467f0b59..d403a7a3021d 100644 --- a/drivers/spi/spi-fsi.c +++ b/drivers/spi/spi-fsi.c @@ -25,6 +25,7 @@ #define SPI_FSI_BASE 0x70000 #define SPI_FSI_INIT_TIMEOUT_MS 1000 +#define SPI_FSI_STATUS_TIMEOUT_MS 100 #define SPI_FSI_MAX_RX_SIZE 8 #define SPI_FSI_MAX_TX_SIZE 40 @@ -299,6 +300,7 @@ static int fsi_spi_transfer_data(struct fsi_spi *ctx, struct spi_transfer *transfer) { int rc = 0; + unsigned long end; u64 status = 0ULL; if (transfer->tx_buf) { @@ -315,10 +317,14 @@ static int fsi_spi_transfer_data(struct fsi_spi *ctx, if (rc) return rc; + end = jiffies + msecs_to_jiffies(SPI_FSI_STATUS_TIMEOUT_MS); do { rc = fsi_spi_status(ctx, &status, "TX"); if (rc) return rc; + + if (time_after(jiffies, end)) + return -ETIMEDOUT; } while (status & SPI_FSI_STATUS_TDR_FULL); sent += nb; @@ -329,10 +335,14 @@ static int fsi_spi_transfer_data(struct fsi_spi *ctx, u8 *rx = transfer->rx_buf; while (transfer->len > recv) { + end = jiffies + msecs_to_jiffies(SPI_FSI_STATUS_TIMEOUT_MS); do { rc = fsi_spi_status(ctx, &status, "RX"); if (rc) return rc; + + if (time_after(jiffies, end)) + return -ETIMEDOUT; } while (!(status & SPI_FSI_STATUS_RDR_FULL)); rc = fsi_spi_read_reg(ctx, SPI_FSI_DATA_RX, &in); |