Mauro Carvalho Chehab 36e3cf0cb1 media: dvb-ttusb-budget: don't use stack for USB transfers
As reported by smatch:

    drivers/media/usb/ttusb-budget/dvb-ttusb-budget.c:311 ttusb_boot_dsp() error: doing dma on the stack (b)
    drivers/media/usb/ttusb-budget/dvb-ttusb-budget.c:321 ttusb_boot_dsp() error: doing dma on the stack (b)
    drivers/media/usb/ttusb-budget/dvb-ttusb-budget.c:330 ttusb_boot_dsp() error: doing dma on the stack (b)
    drivers/media/usb/ttusb-budget/dvb-ttusb-budget.c:351 ttusb_set_channel() error: doing dma on the stack (b)
    drivers/media/usb/ttusb-budget/dvb-ttusb-budget.c:361 ttusb_del_channel() error: doing dma on the stack (b)
    drivers/media/usb/ttusb-budget/dvb-ttusb-budget.c:412 ttusb_init_controller() error: doing dma on the stack (b0)
    drivers/media/usb/ttusb-budget/dvb-ttusb-budget.c:416 ttusb_init_controller() error: doing dma on the stack (b1)
    drivers/media/usb/ttusb-budget/dvb-ttusb-budget.c:422 ttusb_init_controller() error: doing dma on the stack (b2)
    drivers/media/usb/ttusb-budget/dvb-ttusb-budget.c:425 ttusb_init_controller() error: doing dma on the stack (b3)
    drivers/media/usb/ttusb-budget/dvb-ttusb-budget.c:430 ttusb_init_controller() error: doing dma on the stack (get_version)

This driver still uses the USB stack for DMA transfers,
which is broken for a long time. I almost dropped this driver,
as there's a high chance that nobody is using it with upstream
Kernels, as we didn't receive any bug reports.

As fixing this won't be hard, I ended opting to fix.

While here, I dropped an ugly hack that implemented read via
a separate function that was just doing a memcpy().

It should be noticed that, during the init phase, there's
a "b4" register that were never initialized, as its buffer
were used just to store the results of "b3" initialization.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
2020-09-03 11:15:02 +02:00
2020-08-14 19:56:56 -07:00
2020-08-16 13:04:57 -07:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Description
No description provided
Readme 3.4 GiB
Languages
C 97%
Assembly 1%
Shell 0.6%
Rust 0.5%
Python 0.4%
Other 0.3%