Re: [PATCH v2 RFC 0/9] rtw88: Add SDIO support

From: Larry Finger
Date: Fri Mar 10 2023 - 21:16:15 EST


On 3/10/23 14:29, Martin Blumenstingl wrote:
Recently the rtw88 driver has gained locking support for the "slow" bus
types (USB, SDIO) as part of USB support. Thanks to everyone who helped
make this happen!

Based on the USB work (especially the locking part and various
bugfixes) this series adds support for SDIO based cards. It's the
result of a collaboration between Jernej and myself. Neither of us has
access to the rtw88 datasheets. All of our work is based on studying
the RTL8822BS and RTL8822CS vendor drivers and trial and error.

Jernej and myself have tested this with RTL8822BS and RTL8822CS cards.
Other users have confirmed that RTL8821CS support is working as well.
RTL8723DS may also work (we tried our best to handle rtw_chip_wcpu_11n
where needed) but has not been tested at this point.

Jernej's results with a RTL8822BS:
- Main functionality works
- Had a case where no traffic got across the link until he issued a
scan

My results with a RTL8822CS:
- 2.4GHz and 5GHz bands are both working
- TX throughput on a 5GHz network is between 50 Mbit/s and 90 Mbit/s
- RX throughput on a 5GHz network is at 19 Mbit/s (this seems to be
an combination of the location of my board and the cheap antenna
which are both hurting RX performance)

A user shared his results on his own RTL8822CS off-list with me:
- 50Mbit/s throughput in both directions

A user shared his results on RTL8821CS off-list with me:
- 50Mbps down and 25Mbps on a 5GHz network

Why is this an RFC?
- I think it's worth to get another round of feedback from the rtw88
maintainers
- As with most patches: testing is very welcome. If things are working
fine then a Tested-by is appreciated (with some details about the
card, throughput, ...). If something doesn't work for you: please
still report back so we can investigate that problem!

Changes since v1 at [0]:
- removed patches 1-8 as they have been submitted and separately (they
were indepdent and this helped cutting down the size of this series)
- dropped patch "rtw88: ps: Increase LEAVE_LPS_TRY_CNT for SDIO based
chipsets" as the underlying issue has been fixed - most likely with
upstream commit 823092a53556eb ("wifi: rtw88: fix race condition
when doing H2C command")
- rework the code so we don't need a new HCI specific power_switch
callback by utilizing the RTW_FLAG_POWERON flag which was recently
introduced
- various patches include the feedback from reviewers and build
testing robots (see the individual patches for details)


[0] https://lore.kernel.org/lkml/a2449a2d1e664bcc8962af4667aa1290@xxxxxxxxxxx/T/


Jernej Skrabec (1):
wifi: rtw88: Add support for the SDIO based RTL8822BS chipset

Martin Blumenstingl (8):
wifi: rtw88: Clear RTW_FLAG_POWERON early in rtw_mac_power_switch()
wifi: rtw88: sdio: Add HCI implementation for SDIO based chipsets
wifi: rtw88: mac: Support SDIO specific bits in the power on sequence
wifi: rtw88: main: Add the {cpwm,rpwm}_addr for SDIO based chipsets
wifi: rtw88: main: Reserve 8 bytes of extra TX headroom for SDIO cards
mmc: sdio: add Realtek SDIO vendor ID and various wifi device IDs
wifi: rtw88: Add support for the SDIO based RTL8822CS chipset
wifi: rtw88: Add support for the SDIO based RTL8821CS chipset

drivers/net/wireless/realtek/rtw88/Kconfig | 36 +
drivers/net/wireless/realtek/rtw88/Makefile | 12 +
drivers/net/wireless/realtek/rtw88/debug.h | 1 +
drivers/net/wireless/realtek/rtw88/mac.c | 51 +-
drivers/net/wireless/realtek/rtw88/mac.h | 1 -
drivers/net/wireless/realtek/rtw88/main.c | 9 +-
drivers/net/wireless/realtek/rtw88/reg.h | 12 +
.../net/wireless/realtek/rtw88/rtw8821cs.c | 35 +
.../net/wireless/realtek/rtw88/rtw8822bs.c | 35 +
.../net/wireless/realtek/rtw88/rtw8822cs.c | 35 +
drivers/net/wireless/realtek/rtw88/sdio.c | 1251 +++++++++++++++++
drivers/net/wireless/realtek/rtw88/sdio.h | 175 +++
include/linux/mmc/sdio_ids.h | 9 +
13 files changed, 1654 insertions(+), 8 deletions(-)
create mode 100644 drivers/net/wireless/realtek/rtw88/rtw8821cs.c
create mode 100644 drivers/net/wireless/realtek/rtw88/rtw8822bs.c
create mode 100644 drivers/net/wireless/realtek/rtw88/rtw8822cs.c
create mode 100644 drivers/net/wireless/realtek/rtw88/sdio.c
create mode 100644 drivers/net/wireless/realtek/rtw88/sdio.h

Martin,

I am not qualified to review the code, but I am integrating this version into my rtw88 repo at GitHub.com.

It is essential that a successful build is possible after every patch is applied so that an arbitrary bisection will not fail to build. This patch series fails after #2 is committed. File mac.c needs symbol SDIO_LOCAL_OFFSET, which was moved from mac.h to sdio.h. I resolved this be including sdio.h in mac.c. This breaks #3, where you add the include to mac.c. It needs to happen one patch earlier.

The other problem for my repo is that it cannot modify include/linux/mmc/sdio_ids.h, thus I have to create a local sdio_ids.h to contain the new definitions. Once your patches are in the kernel, I will be able to eliminate this work around.

I do not have any rtw88 SDIO devices, thus I will not be able to test, but I will pass any information that I get from my users.

Larry