Hi,
Am 21.12.23 um 16:13 schrieb Florian Fainelli:
On 12/18/2023 10:03 PM, Ivan T. Ivanov wrote:
Borrow SD quirks from vendor Linux driver.
"BCM2712 unfortunately carries with it a perennial bug with the SD
controller register interface present on previous chips
(2711/2709/2708).
Accesses must be dword-sized and a read-modify-write cycle to the 32-bit
registers containing the COMMAND, TRANSFER_MODE, BLOCK_SIZE and
BLOCK_COUNT registers tramples the upper/lower 16 bits of data written.
BCM2712 does not seem to need the extreme delay between each write as on
previous chips, just the serialisation of writes to these registers in a
single 32-bit operation."
Signed-off-by: Ivan T. Ivanov <iiva...@suse.de>
This is diverging from the Linux sdhci-brcmstb.c driver where no such
quirk needs to be carried out, rather the logic for such quirks has
been present in sdhci-iproc.c...
it seems this patch based the downstream kernel changes [1]. I would
suggest to use an existing driver which already handle this bug
(iproc_sdhci or bcm2835_sdhci).
Does the Rpi 5 still works, if the compatible "brcm,bcm2712-sdhci" is
added to mmc/iproc_sdhci.c?
[1] -
https://github.com/raspberrypi/linux/commit/b627647c4500d39cb026924b608841fdf4d4d7e9
