Hi, On Tue, Jul 21, 2015 at 07:17:41PM -0500, Michael Welling wrote: > On Tue, Jul 21, 2015 at 11:34:41AM +0200, Pavel Machek wrote: > > This code has my head spinning. > > I found that the errors do not occur when the driver is built into the kernel. > > I also found that with the patch below the errors go away. > > Not sure if it is acceptible but see if it fixes things on your side. > > > diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c > index cf8b91b..3164d13 100644 > --- a/drivers/spi/spi.c > +++ b/drivers/spi/spi.c > @@ -1801,11 +1801,11 @@ int spi_setup(struct spi_device *spi) > if (!spi->max_speed_hz) > spi->max_speed_hz = spi->master->max_speed_hz; > > - spi_set_cs(spi, false); > - > if (spi->master->setup) > status = spi->master->setup(spi); > > + spi_set_cs(spi, false); > + > dev_dbg(&spi->dev, "setup mode %d, %s%s%s%s%u bits/w, %u Hz max --> %d\n", > (int) (spi->mode & (SPI_CPOL | SPI_CPHA)), > (spi->mode & SPI_CS_HIGH) ? "cs_high, " : "", mh. maybe a runtime PM issue? * external abort on non-linefetch: address cannot be accessed, since the module's clocks are disabled * built-in works, module not: built-in is probably a little bit faster (module must not be loaded from filesystem), so that the device has not yet been suspended * Before 4.2, omap2_mcspi_set_cs() was called in the setup routine, which acquired runtime PM * In 4.2, omap2_mcspi_set_cs() seems to be called without a prior pm_runtime_get_sync() * With your workaround, the device has not yet returned to suspend after the runtime PM acquisition in setup() So I suggest trying the following (compile tested only) patch: -- Sebastian diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c index 5867384..f7d9ffd 100644 --- a/drivers/spi/spi-omap2-mcspi.c +++ b/drivers/spi/spi-omap2-mcspi.c @@ -245,6 +245,7 @@ static void omap2_mcspi_set_enable(const struct spi_device *spi, int enable) static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable) { + struct omap2_mcspi *mcspi = spi_master_get_devdata(spi->master); u32 l; /* The controller handles the inverted chip selects @@ -255,6 +256,8 @@ static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable) enable = !enable; if (spi->controller_state) { + pm_runtime_get_sync(mcspi->dev); + l = mcspi_cached_chconf0(spi); if (enable) @@ -263,6 +266,9 @@ static void omap2_mcspi_set_cs(struct spi_device *spi, bool enable) l |= OMAP2_MCSPI_CHCONF_FORCE; mcspi_write_chconf0(spi, l); + + pm_runtime_mark_last_busy(mcspi->dev); + pm_runtime_put_autosuspend(mcspi->dev); } }
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