linux_dsm_epyc7002/drivers/tty/serial/8250
Wang YanQing 8b5c913f7e serial: 8250_pci: Add WCH CH352 quirk to avoid Xscale detection
The code in 8250.c for detecting ARM/XScale UARTs says:

  * Try writing and reading the UART_IER_UUE bit (b6).
  * If it works, this is probably one of the Xscale platform's
  * internal UARTs.

If the above passes, it then goes on to:

     * It's an Xscale.
     * We'll leave the UART_IER_UUE bit set to 1 (enabled).

However, the CH352 uses the UART_IER_UUE as the LOWPOWER function,
so it is readable and writable.  According to the datasheet:

    "LOWPOWER:When the bit is 1, close the internal benchmark
     clock of serial port to set into low-power status.

So it essentially gets mis-detected as Xscale, and gets
powered down in the process.  The device in question where
this was seen is listed by lspci as:

 Serial controller: Device 4348:3253 (rev 10) (prog-if 02 [16550])

Re-using the 353 quirk which just sets flags to fixed and type
to 16550 is suitable for fixing the 352 as well.

Signed-off-by: Wang YanQing <udknight@gmail.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-03-15 13:27:35 -07:00
..
8250_accent.c
8250_acorn.c tty: remove use of __devexit 2012-11-21 15:27:46 -08:00
8250_boca.c
8250_dma.c serial: 8250_dma: TX optimisation 2013-01-16 07:36:10 -08:00
8250_dw.c Merge 3.8-rc5 into tty-next 2013-01-25 13:27:36 -08:00
8250_early.c drivers/tty/serial/8250: use strlcpy instead of strcpy 2013-01-20 15:50:36 -08:00
8250_em.c tty: remove use of __devexit 2012-11-21 15:27:46 -08:00
8250_exar_st16c554.c
8250_fourport.c
8250_fsl.c
8250_gsc.c 8250: use the 8250 register interface not the legacy one 2012-07-12 14:46:22 -07:00
8250_hp300.c tty: remove use of __devexit 2012-11-21 15:27:46 -08:00
8250_hub6.c
8250_pci.c serial: 8250_pci: Add WCH CH352 quirk to avoid Xscale detection 2013-03-15 13:27:35 -07:00
8250_pnp.c tty/8250_pnp: serial port detection regression since v3.7 2013-03-12 08:53:23 -07:00
8250.c serial: 8250: Keep 8250.<xxxx> module options functional after driver rename 2013-03-12 08:53:23 -07:00
8250.h Merge 3.8-rc5 into tty-next 2013-01-25 13:27:36 -08:00
Kconfig serial: ralink: adds support for the serial core found on ralink wisoc 2013-01-30 00:15:34 -05:00
Makefile serial: 8250: Add support for dmaengine 2013-01-15 23:03:00 -08:00
serial_cs.c 8250: use the 8250 register interface not the legacy one 2012-07-12 14:46:22 -07:00