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spi: meson-spicc: move wait completion in driver to take bursts delay in account

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Some delay occurs between each bursts, thus the default delay is wrong
and a timeout will occur with big enough transfers.

The solution is to handle the timeout management in the driver and
add some delay for each bursts in the timeout calculation.

Reported-by: Da Xue <da@libre.computer>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20221026-spicc-burst-delay-v1-0-1be5ffb7051a@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Neil Armstrong 2022-10-26 09:58:28 +02:00 committed by Mark Brown
parent 195583504b
commit 04694e5002
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 22 additions and 2 deletions
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24
drivers/spi/spi-meson-spicc.c
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@ -160,6 +160,7 @@ struct meson_spicc_device {
struct clk *clk;
struct spi_message *message;
struct spi_transfer *xfer;
struct completion done;
const struct meson_spicc_data *data;
u8 *tx_buf;
u8 *rx_buf;
@ -282,7 +283,7 @@ static irqreturn_t meson_spicc_irq(int irq, void *data)
/* Disable all IRQs */
writel(0, spicc->base + SPICC_INTREG);
spi_finalize_current_transfer(spicc->master);
complete(&spicc->done);
return IRQ_HANDLED;
}
@ -386,6 +387,7 @@ static int meson_spicc_transfer_one(struct spi_master *master,
struct spi_transfer *xfer)
{
struct meson_spicc_device *spicc = spi_master_get_devdata(master);
unsigned long timeout;
/* Store current transfer */
spicc->xfer = xfer;
@ -410,13 +412,29 @@ static int meson_spicc_transfer_one(struct spi_master *master,
/* Setup burst */
meson_spicc_setup_burst(spicc);
/* Setup wait for completion */
reinit_completion(&spicc->done);
/* For each byte we wait for 8 cycles of the SPI clock */
timeout = 8LL * MSEC_PER_SEC * xfer->len;
do_div(timeout, xfer->speed_hz);
/* Add 10us delay between each fifo bursts */
timeout += ((xfer->len >> 4) * 10) / MSEC_PER_SEC;
/* Increase it twice and add 200 ms tolerance */
timeout += timeout + 200;
/* Start burst */
writel_bits_relaxed(SPICC_XCH, SPICC_XCH, spicc->base + SPICC_CONREG);
/* Enable interrupts */
writel_relaxed(SPICC_TC_EN, spicc->base + SPICC_INTREG);
return 1;
if (!wait_for_completion_timeout(&spicc->done, msecs_to_jiffies(timeout)))
return -ETIMEDOUT;
return 0;
}
static int meson_spicc_prepare_message(struct spi_master *master,
@ -743,6 +761,8 @@ static int meson_spicc_probe(struct platform_device *pdev)
spicc->pdev = pdev;
platform_set_drvdata(pdev, spicc);
init_completion(&spicc->done);
spicc->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(spicc->base)) {
dev_err(&pdev->dev, "io resource mapping failed\n");