Re: [RFC PATCH v2] ath9k: add loader for AR92XX (and older) pci(e)

From: Julian Calaby <julian.calaby@gmail.com>
To: Christian Lamparter <chunkeey@gmail.com>
Cc: QCA ath9k Development <ath9k-devel@qca.qualcomm.com>,
	linux-wireless@vger.kernel.org, Hauke Mehrtens <hauke@hauke-m.de>,
	Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Subject: Re: [RFC PATCH v2] ath9k: add loader for AR92XX (and older) pci(e)
Date: Sun, 9 Jun 2019 23:28:53 +1000	[thread overview]
Message-ID: <CAGRGNgXNQK_cHL1pcjyjc-7h+a49zXtTjcv48EDatHSdaSc+2w@mail.gmail.com> (raw)
In-Reply-To: <20190608144947.744-2-chunkeey@gmail.com>

Hi Christian,

On Sun, Jun 9, 2019 at 12:49 AM Christian Lamparter <chunkeey@gmail.com> wrote:
>
> Atheros cards with a AR92XX generation (and older) chip usually
> store their pci(e) initialization vectors on an external eeprom chip.
> However these chips technically don't need the eeprom chip attached,
> the AR9280 Datasheet in section "6.1.2 DEVICE_ID" describes that
> "... if the EEPROM content is not valid, a value of 0XFF1C returns
> when read from the register". So the embedded devices like routers
> and accesspoint usually have the pci(e) initialization vectors
> stored on the system's FLASH, which is out of reach of the ath9k
> chip.
>
> Furthermore, Some devices (like the Cisco Meraki Z1 Cloud Managed
> Teleworker Gateway) need to be able to initialize the PCIe wifi device.
> Normally, this should be done as a pci quirk during the early stages of
> booting linux. However, this isn't possible for devices which have the
> init code for the Atheros chip stored on NAND in an UBI volume.
> Hence, this module can be used to initialize the chip when the
> user-space is ready to extract the init code.
>
> Martin Blumenstingl prodived the following fixes:
> owl-loader: add support for OWL emulation PCI devices
> owl-loader: don't re-scan the bus when ath9k_pci_fixup failed
> owl-loader: use dev_* instead of pr_* logging functions
> owl-loader: auto-generate the eeprom filename as fallback
> owl-loader: add a debug message when swapping the eeprom data
> owl-loader: add missing newlines in log messages
>
> Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> ---
> v2: address Julian Calaby's comments:
>     - make it a separate driver again (much like OpenWrt)
>     - remove ar71xx leftovers (pdata)

This looks sane to me. Thanks for splitting it out.

Reviewed-by: Julian Calaby <julian.calaby@gmail.com>

> ---
>  drivers/net/wireless/ath/ath9k/Kconfig        |  16 ++
>  drivers/net/wireless/ath/ath9k/Makefile       |   2 +
>  .../wireless/ath/ath9k/ath9k_pci_owl_loader.c | 215 ++++++++++++++++++
>  3 files changed, 233 insertions(+)
>  create mode 100644 drivers/net/wireless/ath/ath9k/ath9k_pci_owl_loader.c
>
> diff --git a/drivers/net/wireless/ath/ath9k/ath9k_pci_owl_loader.c b/drivers/net/wireless/ath/ath9k/ath9k_pci_owl_loader.c
> new file mode 100644
> index 000000000000..7ed495a9f1fe
> --- /dev/null
> +++ b/drivers/net/wireless/ath/ath9k/ath9k_pci_owl_loader.c
> @@ -0,0 +1,215 @@
> +module_pci_driver(owl_driver);
> +MODULE_AUTHOR("Christian Lamparter <chunkeey@gmail.com>");
> +MODULE_DESCRIPTION("Initializes Atheros' Owl Emulation devices");

Tiniest nit: something like "External EEPROM data loader for Atheros
AR500X to AR92XX" would make more sense to someone who isn't familiar
with the hardware.

Thanks,

-- 
Julian Calaby

Email: julian.calaby@gmail.com
Profile: http://www.google.com/profiles/julian.calaby/