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authorUdit Kumar <u-kumar1@ti.com>2024-06-25 21:37:25 +0530
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2024-07-05 09:14:52 +0200
commit500bfbababce373fb7886e76c17d40187d8bbfc8 (patch)
tree42a1819b93c0ddca6cfcfe81c8786466f1f2c92a
parentc3507e8da743be4208d065a1be32d2b8828229ca (diff)
serial: 8250_omap: Fix Errata i2310 with RX FIFO level check
commit c128a1b0523b685c8856ddc0ac0e1caef1fdeee5 upstream. Errata i2310[0] says, Erroneous timeout can be triggered, if this Erroneous interrupt is not cleared then it may leads to storm of interrupts. Commit 9d141c1e6157 ("serial: 8250_omap: Implementation of Errata i2310") which added the workaround but missed ensuring RX FIFO is really empty before applying the errata workaround as recommended in the errata text. Fix this by adding back check for UART_OMAP_RX_LVL to be 0 for workaround to take effect. [0] https://www.ti.com/lit/pdf/sprz536 page 23 Fixes: 9d141c1e6157 ("serial: 8250_omap: Implementation of Errata i2310") Cc: stable@vger.kernel.org Reported-by: Vignesh Raghavendra <vigneshr@ti.com> Closes: https://lore.kernel.org/all/e96d0c55-0b12-4cbf-9d23-48963543de49@ti.com/ Signed-off-by: Udit Kumar <u-kumar1@ti.com> Link: https://lore.kernel.org/r/20240625160725.2102194-1-u-kumar1@ti.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/tty/serial/8250/8250_omap.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index d2abde8c83aa..1f389670dfdf 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -651,7 +651,8 @@ static irqreturn_t omap8250_irq(int irq, void *dev_id)
* https://www.ti.com/lit/pdf/sprz536
*/
if (priv->habit & UART_RX_TIMEOUT_QUIRK &&
- (iir & UART_IIR_RX_TIMEOUT) == UART_IIR_RX_TIMEOUT) {
+ (iir & UART_IIR_RX_TIMEOUT) == UART_IIR_RX_TIMEOUT &&
+ serial_port_in(port, UART_OMAP_RX_LVL) == 0) {
unsigned char efr2, timeout_h, timeout_l;
efr2 = serial_in(up, UART_OMAP_EFR2);