On Mon, Mar 2, 2020 at 9:41 PM Wolfgang Wallner <wolfgang.wall...@br-automation.com> wrote: > > Currently the ofdata_to_platdata() method calls dev_read_addr_pci(), > which potentially accesses the parent PCI bus. If this happens before > the parent PCI bus is probed the resulting address will be wrong. > > This behavior was triggered by commit 82de42fa1468 ("dm: core: > Allocate parent data separate from probing parent"). > > According to a comment in drivers/pci/pci-uclass.c [1] accessing > the PCI parent bus in ofdata_to_platdata() is not allowed, and the > access should be moved to the probe() function. > > Move the call to dev_read_addr_pci() and the related handling of the > 'addr' value from the ofdata_to_platdata() to its own function, > which is then called from the probe() method. > > While moving the code, the comment /* try Processor Local Bus device > first */ was dropped. It was initially added with commit 3db886a5bf38 > ("serial: ns16550: Support ns16550 compatible pci uart devices") and > later made obsolete with commit 33c215af4b9d ("dm: pci: Add a function > to read a PCI BAR"). > > [1] Comment in drivers/pci/pci-uclass.c: > "A common cause of this problem is that this function is called in the > ofdata_to_platdata() method of @dev. Accessing the PCI bus in that > method is not allowed, since it has not yet been probed. To fix this, > move that access to the probe() method of @dev instead." > > Signed-off-by: Wolfgang Wallner <wolfgang.wall...@br-automation.com> > > Fixes: 82de42fa1468 ("dm: core: Allocate parent data separate from > probing parent") > > --- > The discussion leading to this patch is located at > https://lists.denx.de/pipermail/u-boot/2020-February/399811.html > > I have moved the code from probe() to a new function called > ns1655_serial_set_base_addr() to keep the probe() simple. > > Changes in v2: > - Fixed build guards > - Moved code from probe() to a new function called > ns1655_serial_set_base_addr() to keep the probe() simple > - Removed RFC tag > > drivers/serial/ns16550.c | 40 ++++++++++++++++++++++++++++------------ > 1 file changed, 28 insertions(+), 12 deletions(-) >
Reviewed-by: Bin Meng <bmeng...@gmail.com> Tested-by: Bin Meng <bmeng...@gmail.com> # Tested on Intel Galileo