[PATCH v2] cfi_flash: Fix devicetree address determination

[Stefan Roese]

On 08.10.20 10:39, Heinrich Schuchardt wrote:
> On 08.10.20 09:08, Stefan Roese wrote:
>> On 24.09.20 01:22, Andre Przywara wrote:
>>> The cfi-flash driver uses an open-coded version of the generic
>>> algorithm to decode and translate multiple frames of a "reg" property.
>>>
>>> This starts off the wrong foot by using the address-cells and size-cells
>>> properties of *this* very node, and not of the parent. This somewhat
>>> happened to work back when we were using a wrong default size of 2,
>>> but broke about a year ago with commit 0ba41ce1b781 ("libfdt: return
>>> correct value if #size-cells property is not present").
>>>
>>> Instead of fixing the reinvented wheel, just use the generic function
>>> that does all of this properly.
>>>
>>> This fixes U-Boot on QEMU (-arm64), which was crashing due to decoding
>>> a wrong flash base address:
>>> DRAM:  1 GiB
>>> Flash: "Synchronous Abort" handler, esr 0x96000044
>>> elr: 00000000000211dc lr : 00000000000211b0 (reloc)
>>> elr: 000000007ff5e1dc lr : 000000007ff5e1b0
>>> x0 : 00000000000000f0 x1 : 000000007ff5e1d8
>>> x2 : 000000007edfbc48 x3 : 0000000000000000
>>> x4 : 0000000000000000 x5 : 00000000000000f0
>>> x6 : 000000007edfbc2c x7 : 0000000000000000
>>> x8 : 000000007ffd8d70 x9 : 000000000000000c
>>> x10: 0400000000000003 x11: 0000000000000055
>>>        ^^^^^^^^^^^^^^^^
>>>
>>> Signed-off-by: Andre Przywara <andre.przywara at arm.com>
>>
>> Applied to u-boot-cfi-flash/master
>>
>> Thanks,
>> Stefan
>>
>>> ---
>>> Changes v1 .. v2:
>>> - Use live tree compatible function
>>> - Drop unneeded size variable
>>>
>>>    drivers/mtd/cfi_flash.c | 24 ++++++------------------
>>>    1 file changed, 6 insertions(+), 18 deletions(-)
>>>
>>> diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
>>> index b7289ba5394..9e3a652f445 100644
>>> --- a/drivers/mtd/cfi_flash.c
>>> +++ b/drivers/mtd/cfi_flash.c
>>> @@ -2468,29 +2468,17 @@ unsigned long flash_init(void)
>>>    #ifdef CONFIG_CFI_FLASH /* for driver model */
>>>    static int cfi_flash_probe(struct udevice *dev)
>>>    {
>>> -    const fdt32_t *cell;
>>> -    int addrc, sizec;
>>> -    int len, idx;
>>> +    fdt_addr_t addr;
>>> +    int idx;
>>>    -    addrc = dev_read_addr_cells(dev);
>>> -    sizec = dev_read_size_cells(dev);
>>> -
>>> -    /* decode regs; there may be multiple reg tuples. */
>>> -    cell = dev_read_prop(dev, "reg", &len);
>>> -    if (!cell)
>>> -        return -ENOENT;
>>> -    idx = 0;
>>> -    len /= sizeof(fdt32_t);
>>> -    while (idx < len) {
>>> -        phys_addr_t addr;
>>> -
>>> -        addr = dev_translate_address(dev, cell + idx);
>>> +    for (idx = 0; idx < CFI_MAX_FLASH_BANKS; idx++) {
>>> +        addr = dev_read_addr_index(dev, idx);
> 
> Why don't you additionally read the size here to populate flash_info[].size?
> 
> fdt_size_t size;
> addr = dev_read_addr_size_index(dev, idx, &size);

It was not done before this either. IIRC, then the size is auto detected
by querying the flash chip.

Do you see any issue without this? Feel free to send a follow up patch
is something needs to get fixed / tuned.

Thanks,
Stefan