Hi Rudolf, On Wed, 18 Mar 2020 at 05:25, Rudolf J Streif <[email protected]> wrote: > > I ran into an issue today with a U-CLASS SPI NOR flash device on a NXP > FlexSPI controller. U-Boot started correctly from the flash device but > using 'sf probe 0:0' would always return 'Invalid bus 0 (err=-19)'. This > error message is emitted by spi_get_bus_and_cs() in > drivers/spi/spi-uclass.c. I traced the issue to > uclass_get_device_by_seq() in drivers/core/uclass.c. > > The function first searches the device list for a device that already > claimed the sequence number (dev->seq). If not found it would look if a > device requested that sequence number (dev->seq_req). That would always > fail for my device. The bus had not been probed yet and hence dev->seq > was -1 and the device also had dev->req_seq set to -1. > > The board is using a device tree hence it would only make sense to set > the requested sequence number via the device tree. However, there is no > such thing and even if there was it might not be specified. > > Consequently, the device was never probed although the driver was > correctly set up via device tree. > > I worked around it by simply setting dev->req_seq of the first device > that had it set to -1 to the sequence number the search function was > looking for (see patch below). It solved my problem but I don't know if > that is the right way of addressing it. I could not find any other > solution for this particular problem anywhere. > > Rudi
You can put the SPI flash in the device tree with an alias pointing to it.. That is the intended way with driver model. Regards, SImon > > > > From 0f05ab964fcc7d29d8d467e663d7daa72328cf66 Mon Sep 17 00:00:00 2001 > From: Rudolf J Streif <[email protected]> > Date: Tue, 17 Mar 2020 17:13:07 -0700 > Subject: [PATCH] Fix issue with SPI device sequence number > > If the requested sequence number for a SPI device was -1 (any) > then the device would never be probed. This fix simply assigns > the sequence number asked for at probing to the device if it has > not been probed yet and the requested sequence number is -1. > > Signed-off-by: Rudolf J Streif <[email protected]> > --- > drivers/core/uclass.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/core/uclass.c b/drivers/core/uclass.c > index fc3157de39..e791103153 100644 > --- a/drivers/core/uclass.c > +++ b/drivers/core/uclass.c > @@ -310,6 +310,8 @@ int uclass_find_device_by_seq(enum uclass_id id, int > seq_or_req_seq, > > uclass_foreach_dev(dev, uc) { > debug(" - %d %d '%s'\n", dev->req_seq, dev->seq, > dev->name); > + if (find_req_seq && dev->req_seq == -1) > + dev->req_seq = seq_or_req_seq; > if ((find_req_seq ? dev->req_seq : dev->seq) == > seq_or_req_seq) { > *devp = dev; > -- > 2.23.0 > > >
