On 09/25/2015 02:36 AM, Przemyslaw Marczak wrote:
Hello Stephen,
On 09/24/2015 07:29 PM, Stephen Warren wrote:
On 09/24/2015 09:29 AM, Przemyslaw Marczak wrote:
After rework in lib/fdtdec.c, the function fdtdec_get_addr() doesn't work for nodes with #size-cells property, set to 0.
To get GPIO's 'reg' property, the code should use one of: fdtdec_get_addr_size_auto_no/parent() function.
Fortunately dm core provides a function to get the property.
This commit reworks function gpio_exynos_bind(), to properly use dev_get_addr() for GPIO device.
This prevents setting a wrong base register for Exynos GPIOs.
Migrating everything to dev_get_addr() is the correct long-term fix, so this patch,
Acked-by: Stephen Warren swarren@nvidia.com
... although I'd have liked to see a smaller diff that didn't both re-order all the code /and/ call a different function, but I suppose that's not possible given the need to pass the device object to dev_get_addr(). You could have used fdtdec_get_addr_size_auto_parent() directly.
Yes, it's not a single line diff, but the driver supports driver-model, so it's natural that it should use driver model API if can, instead of fdtdec API.
This approach makes things easier to test and catch mistakes in the future.
I think it'd be good to fix fdtdec_get_addr_size() to have the same semantics that it previously did. There might be other code in U-Boot that's affected by the same issue, and fixing fdtdec_get_addr_size() would make sure that all got fixed too. Are you willing to send that patch too?
Essentially, fdtdec_get_addr_size() used to assume:
#address-cells == sizeof(fdt_addr_t) if sizep == NULL: #size-cells == 0 else: #size-cells == sizeof(fdt_addr_t)
However, it now assumes:
#address-cells == sizeof(fdt_addr_t) #size-cells == sizeof(fdt_addr_t)
Let's just add that condition back by doing something like the following in fdtdec_get_addr_size():
u32 ns;
if (sizep) ns = sizeof(fdt_size_t) / sizeof(fdt32_t); else ns = 0;
... and replacing the ns parameter that's passed to fdtdec_get_addr_size_fixed() with that variable, rather than hard-coding it.
Sorry, currently I have some other things to do, and I wouldn't prefer fixing this without proper testing. Such core things should be tested in sandbox by couple of unit tests.
OK, I'll take a stab at it.
This seem to be okay, but is still wrong.
We should always call fdtdec_get_addr_size_fixed() with arguments, which fits to the dtb, instead of hardcoded values.
So, only the implementation of function
fdtdec_get_addr_size_auto_parent()
seem to be correct.
It check the real #address-cells and #size-cells.
Right. All "client" code should be migrated to call function which look at #address-cells and #size-cells. That's what fdtdec_get_addr_size_auto_parent(), fdtdec_get_addr_size_auto_noparent(), and dev_get_addr() do.
However, there is code in U-Boot which (incorrectly) used fdtdec_get_addr() to parse properties other than reg. Those properties aren't affected by #address-cells and #size-cells. Hence, the hard-coding of na and ns inside fdtdec_get_addr_size() is required to support those use-case. Hopefully once everything that parses reg is migrated to the functions that look at #address-cells and #size-cells, fdtdec_get_addr_size() can be renamed to make it obvious it shouldn't be used for parsing reg.
If this is slow, then maybe we need some cache with nodes, its parents/childs and its size/addr cells to be checked only once?
Hopefully all (or almost all) use-cases can use dev_get_addr(). There's no slowness there, since there's no searching of the DT to find the parent; it's already known directly.