Hi Cov,
The same PL011 driver will be used in virtutal machine, make sure your
changes have no side effects in VM.
On 02/07/2017 10:07 PM, Timur Tabi wrote:
Christopher Covington wrote:
The previous change worked around QDF2432v1 and QDF2400v1 SoC erratum 44
for the full-fledged console, when UART AMBA Port (UAP) data is
available.
Additionally provide a workaround the earlycon case, again checking
TXFE ==
0 instead of BUSY == 1. As earlycon is operating before UAP data is
available, the implementation is different than in the preceding patch.
Signed-off-by: Christopher Covington <cov@xxxxxxxxxxxxxx>
---
drivers/tty/serial/amba-pl011.c | 28 +++++++++++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)
diff --git a/drivers/tty/serial/amba-pl011.c
b/drivers/tty/serial/amba-pl011.c
index 41e51901d6ef..f25e7c994f8e 100644
--- a/drivers/tty/serial/amba-pl011.c
+++ b/drivers/tty/serial/amba-pl011.c
@@ -2411,6 +2411,29 @@ static bool qdf2400_e44(void) {
cpu_var_model == MIDR_QCOM_FALKOR_V1);
}
+#ifdef CONFIG_QCOM_QDF2400_ERRATUM_44
+static void qdf2400_e44_putc(struct uart_port *port, int c)
+{
+ while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
+ cpu_relax();
+ if (port->iotype == UPIO_MEM32)
+ writel(c, port->membase + UART01x_DR);
+ else
+ writeb(c, port->membase + UART01x_DR);
I believe 32-bit writes are safe on QDF2400v1, so I think you
technically don't need the UPIO_MEM32 check. Just always call writel.
+ while (!(readl(port->membase + UART01x_FR) & UART011_FR_TXFE))
+ cpu_relax();
+}
+
+static void qdf2400_e44_early_write(struct console *con, const char
*s, unsigned n)
+{
+ struct earlycon_device *dev = con->data;
+
+ uart_console_write(&dev->port, s, n, qdf2400_e44_putc);
+}
+#else
+#define qdf2400_e44_early_write pl011_early_write
+#endif
Same with patch 1/2. If you change qdf2400_e44(), you don't need the
#else block.
+
static void pl011_putc(struct uart_port *port, int c)
{
while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
@@ -2436,7 +2459,10 @@ static int __init
pl011_early_console_setup(struct earlycon_device *device,
if (!device->port.membase)
return -ENODEV;
- device->con->write = pl011_early_write;
+ if (qdf2400_e44())
+ device->con->write = qdf2400_e44_early_write;
+ else
+ device->con->write = pl011_early_write;
return 0;
}
OF_EARLYCON_DECLARE(pl011, "arm,pl011", pl011_early_console_setup);
--
Shanker Donthineni
Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc.
Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project.
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