| Message ID | 1411060140-2801-6-git-send-email-andriy.shevchenko@linux.intel.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
On Thu, Sep 18, 2014 at 08:08:55PM +0300, Andy Shevchenko wrote: > Always disable all interrupts before pump message. Enable them only for PIO > mode. Why? It's also not very obvious looking at the diff how this actually works, the connection between DMA based transfer and interrupt disabling is not clear.
On Wed, 2014-09-24 at 09:47 +0100, Mark Brown wrote: > On Thu, Sep 18, 2014 at 08:08:55PM +0300, Andy Shevchenko wrote: > > > Always disable all interrupts before pump message. Enable them only for PIO > > mode. > > Why? > > It's also not very obvious looking at the diff how this actually works, > the connection between DMA based transfer and interrupt disabling is > not clear. It's a really good question and needs to be investigated more. If I don't disable interrupts I'm getting sometimes overrun/underrun interrupt. But we have no proper transfer handler in case of DMA. Perhaps we should carefully handle that case.
diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c index 0960cc7..d58edfe 100644 --- a/drivers/spi/spi-dw.c +++ b/drivers/spi/spi-dw.c @@ -342,6 +342,13 @@ static irqreturn_t dw_spi_irq(int irq, void *dev_id) return dws->transfer_handler(dws); } +static void dw_spi_disable_intr(struct dw_spi *dws) +{ + spi_enable_chip(dws, 0); + spi_mask_intr(dws, 0xff); + spi_enable_chip(dws, 1); +} + /* Must be called inside pump_transfers() */ static void poll_transfer(struct dw_spi *dws) { @@ -474,6 +481,9 @@ static void pump_transfers(unsigned long data) dws->transfer_handler = interrupt_transfer; } + /* Disable all interrupts first */ + dw_spi_disable_intr(dws); + /* * Reprogram registers only if * 1. chip select changes @@ -490,7 +500,6 @@ static void pump_transfers(unsigned long data) spi_chip_sel(dws, spi, 1); /* Set the interrupt mask, for poll mode just disable all int */ - spi_mask_intr(dws, 0xff); if (imask) spi_umask_intr(dws, imask); if (txint_level) @@ -611,9 +620,7 @@ static void dw_spi_cleanup(struct spi_device *spi) /* Restart the controller, disable all interrupts, clean rx fifo */ static void spi_hw_init(struct dw_spi *dws) { - spi_enable_chip(dws, 0); - spi_mask_intr(dws, 0xff); - spi_enable_chip(dws, 1); + dw_spi_disable_intr(dws); /* * Try to detect the FIFO depth if not set by interface driver,
Always disable all interrupts before pump message. Enable them only for PIO mode. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- drivers/spi/spi-dw.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-)