diff options
| author | Yogesh Lal <ylal@codeaurora.org> | 2014-06-27 12:07:51 +0530 |
|---|---|---|
| committer | Marc Jones <marc.jones@se-eng.com> | 2015-03-13 23:01:39 +0100 |
| commit | 419fa61f370072d82c037f84d8f89d0c4c23480b (patch) | |
| tree | 9ec156af538bf5f4dd761155518ba52b35e9b908 /payloads/libpayload/drivers/serial | |
| parent | 586d6e2a8800f29cdfb6111a91d6e8fc8f4fc43c (diff) | |
libpayload: ipq808x: stale interrupt shall not be cleared unconditionally
The serial driver hangs in cases when FIFO has more than single word to be
processed. Easiest way to reproduce is to paste a string of greater than 4
characters in cli.
Clearing the RXSTALE interrupt without draining all the characters from FIFO
leads to the issue as the driver is dependent on msm_boot_uart_dm_read
function to reinitialize for next transfer.
Logically the driver is organized in such a manner that next transfer never
gets initiated till rx_data_read < total_rx_data. Clearing the RXSTALE without
consideration of total number of characters (or words) unprocessed makes the
msm_boot_uart_dm_read to return on the first if conditional. Thus the driver is
stuck forever.
A quick fix is to avoid clearing the stale interrupt. Reset is handled whenever
a new transfer is initialized in msm_boot_uart_dm_init_rx_transfer.
BUG=chrome-os-partner:29542
TEST=manual
-Paste a string greater than 4 characters in cli.
Original-Change-Id: I016afb01a77cd14764f0176f6bf144fb29796c2f
Original-Signed-off-by: Yogesh Lal <ylal@codeaurora.org>
Original-Reviewed-on: https://chromium-review.googlesource.com/209512
Original-Reviewed-by: Vadim Bendebury <vbendeb@chromium.org>
Original-Commit-Queue: Vadim Bendebury <vbendeb@chromium.org>
Original-Tested-by: Vadim Bendebury <vbendeb@chromium.org>
(cherry picked from commit 61528884ad2c0a8e146054bbfeb01a3bc73b9692)
Signed-off-by: Marc Jones <marc.jones@se-eng.com>
Change-Id: I936af5daa52a25f62133bdf9fb44f0b68cf34e88
Reviewed-on: http://review.coreboot.org/8667
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Diffstat (limited to 'payloads/libpayload/drivers/serial')
| -rw-r--r-- | payloads/libpayload/drivers/serial/ipq806x.c | 3 |
1 files changed, 0 insertions, 3 deletions
diff --git a/payloads/libpayload/drivers/serial/ipq806x.c b/payloads/libpayload/drivers/serial/ipq806x.c index 834389ec0e..912893d7e2 100644 --- a/payloads/libpayload/drivers/serial/ipq806x.c +++ b/payloads/libpayload/drivers/serial/ipq806x.c @@ -152,9 +152,6 @@ static unsigned msm_boot_uart_dm_read(void) return IPQ_UART_DM_E_RX_NOT_READY; } - /* Clear stale event. */ - writel(IPQ_UART_DM_CMD_RES_STALE_INT, IPQ_UART_DM_CR(base)); - /* Read UART_DM_RX_TOTAL_SNAP for actual number of bytes received */ if (total_rx_data == 0) total_rx_data = readl(IPQ_UART_DM_RX_TOTAL_SNAP(base)); |