The spi_get_bus_and_cs() may be called on the same bus and chipselect with different frequency or mode. This is valid usecase, but the code fails to notify the controller of such a configuration change. Call spi_set_speed_mode() in case bus frequency or bus mode changed to let the controller update the configuration.
The problem can easily be triggered using the sspi command: => sspi 0:0@1000 => sspi 0:0@2000 Without this patch, both transfers happen at 1000 Hz. With this patch, the later transfer happens correctly at 2000 Hz.
Signed-off-by: Marek Vasut marex@denx.de Cc: Jagan Teki jagan@amarulasolutions.com Cc: Patrick Delaunay patrick.delaunay@st.com --- V2: - Use bus_data->speed for the check - Release the bus on error --- drivers/spi/spi-uclass.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/drivers/spi/spi-uclass.c b/drivers/spi/spi-uclass.c index 7155d4aebd6..5617f6645ee 100644 --- a/drivers/spi/spi-uclass.c +++ b/drivers/spi/spi-uclass.c @@ -405,12 +405,22 @@ int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode, goto err; }
+ /* In case bus frequency or mode changed, update it. */ + if ((speed && bus_data->speed && bus_data->speed != speed) || + (plat->mode != mode)) { + ret = spi_set_speed_mode(bus, speed, mode); + if (ret) + goto err_speed_mode; + } + *busp = bus; *devp = slave; log_debug("%s: bus=%p, slave=%p\n", __func__, bus, *devp);
return 0;
+err_speed_mode: + spi_release_bus(slave); err: log_debug("%s: Error path, created=%d, device '%s'\n", __func__, created, dev->name);