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| author | Wang YanQing <udknight@gmail.com> | 2013-03-05 19:16:48 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-16 00:27:35 +0400 |
| commit | 8b5c913f7ee6464849570bacb6bcd9ef0eaf7dce (patch) | |
| tree | a6e5606366198d24be5ece4bce3bfe0ae677716d /drivers/tty | |
| parent | 503bded92da283b2f31d87e054c4c6d30c3c2340 (diff) | |
| download | linux-8b5c913f7ee6464849570bacb6bcd9ef0eaf7dce.tar.xz | |
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>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/8250/8250_pci.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c index aa76825229dc..26e3a97ab157 100644 --- a/drivers/tty/serial/8250/8250_pci.c +++ b/drivers/tty/serial/8250/8250_pci.c @@ -1554,6 +1554,7 @@ pci_wch_ch353_setup(struct serial_private *priv, #define PCI_DEVICE_ID_PLX_CRONYX_OMEGA 0xc001 #define PCI_DEVICE_ID_INTEL_PATSBURG_KT 0x1d3d #define PCI_VENDOR_ID_WCH 0x4348 +#define PCI_DEVICE_ID_WCH_CH352_2S 0x3253 #define PCI_DEVICE_ID_WCH_CH353_4S 0x3453 #define PCI_DEVICE_ID_WCH_CH353_2S1PF 0x5046 #define PCI_DEVICE_ID_WCH_CH353_2S1P 0x7053 @@ -2172,6 +2173,14 @@ static struct pci_serial_quirk pci_serial_quirks[] __refdata = { .subdevice = PCI_ANY_ID, .setup = pci_wch_ch353_setup, }, + /* WCH CH352 2S card (16550 clone) */ + { + .vendor = PCI_VENDOR_ID_WCH, + .device = PCI_DEVICE_ID_WCH_CH352_2S, + .subvendor = PCI_ANY_ID, + .subdevice = PCI_ANY_ID, + .setup = pci_wch_ch353_setup, + }, /* * ASIX devices with FIFO bug */ @@ -4870,6 +4879,10 @@ static struct pci_device_id serial_pci_tbl[] = { PCI_ANY_ID, PCI_ANY_ID, 0, 0, pbn_b0_bt_2_115200 }, + { PCI_VENDOR_ID_WCH, PCI_DEVICE_ID_WCH_CH352_2S, + PCI_ANY_ID, PCI_ANY_ID, + 0, 0, pbn_b0_bt_2_115200 }, + /* * Commtech, Inc. Fastcom adapters */ |