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authorMarc Kleine-Budde <mkl@pengutronix.de>2021-01-05 22:41:38 +0100
committerMarc Kleine-Budde <mkl@pengutronix.de>2021-01-07 11:02:09 +0100
commit2fbb397f584077e3c90abd06829f5a1f66fdd5f4 (patch)
treedd5cb7cb0f2d8156681b2ec3cd92dd61f82e8128 /drivers/net/can
parentcan: mcp251xfd: mcp251xfd_handle_tefif(): fix TEF vs. TX race condition (diff)
downloadlinux-2fbb397f584077e3c90abd06829f5a1f66fdd5f4.tar.xz
linux-2fbb397f584077e3c90abd06829f5a1f66fdd5f4.zip
can: mcp251xfd: mcp251xfd_handle_rxif_ring(): first increment RX tail pointer in HW, then in driver
The previous patch fixes a TEF vs. TX race condition, by first updating the TEF tail pointer in hardware, and then updating the driver internal pointer. The same pattern exists in the RX-path, too. This should be no problem, as the driver accesses the RX-FIFO from the interrupt handler only, thus the access is properly serialized. Fix the order here, too, so that the TEF- and RX-path look similar. Fixes: 1f652bb6bae7 ("can: mcp25xxfd: rx-path: reduce number of SPI core requests to set UINC bit") Link: https://lore.kernel.org/r/20210105214138.3150886-3-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Diffstat (limited to 'drivers/net/can')
-rw-r--r--drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
index 85a1a8b7c0e7..36235afb0bc6 100644
--- a/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
+++ b/drivers/net/can/spi/mcp251xfd/mcp251xfd-core.c
@@ -1552,10 +1552,8 @@ mcp251xfd_handle_rxif_ring(struct mcp251xfd_priv *priv,
/* Increment the RX FIFO tail pointer 'len' times in a
* single SPI message.
- */
- ring->tail += len;
-
- /* Note:
+ *
+ * Note:
*
* "cs_change == 1" on the last transfer results in an
* active chip select after the complete SPI
@@ -1571,6 +1569,8 @@ mcp251xfd_handle_rxif_ring(struct mcp251xfd_priv *priv,
last_xfer->cs_change = 1;
if (err)
return err;
+
+ ring->tail += len;
}
return 0;