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@foss.st.com --- V2: Set plat in case it is NULL --- drivers/spi/spi-uclass.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)
diff --git a/drivers/spi/spi-uclass.c b/drivers/spi/spi-uclass.c index ee30110b56..d867b27806 100644 --- a/drivers/spi/spi-uclass.c +++ b/drivers/spi/spi-uclass.c @@ -391,6 +391,8 @@ int spi_get_bus_and_cs(int busnum, int cs, int speed, int mode, } else if (ret) { dev_err(bus, "Invalid chip select %d:%d (err=%d)\n", busnum, cs, ret); return ret; + } else if (dev) { + plat = dev_get_parent_plat(dev); }
if (!device_active(dev)) { @@ -416,12 +418,22 @@ 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 && 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);