From: Wang YanQing Date: Tue, 5 Mar 2013 15:16:48 +0000 (+0800) Subject: serial: 8250_pci: Add WCH CH352 quirk to avoid Xscale detection X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=8b5c913f7ee6464849570bacb6bcd9ef0eaf7dce;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git 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 Signed-off-by: Paul Gortmaker Signed-off-by: Greg Kroah-Hartman --- 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 */