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author | Giuseppe CAVALLARO <peppe.cavallaro@st.com> | 2016-11-14 11:27:29 +0300 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2016-11-16 03:56:17 +0300 |
commit | ba1ffd74df74a9efa5290f87632a0ed55f1aa387 (patch) | |
tree | bd2191959ebcd1b1cc75566fb7767de054a50e81 /drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c | |
parent | d2042052a0aa6a54f01a0c9e14243ec040b100e2 (diff) | |
download | linux-ba1ffd74df74a9efa5290f87632a0ed55f1aa387.tar.xz |
stmmac: fix PTP support for GMAC4
Due to bad management of the descriptors, when use ptp4l,
kernel panics as shown below:
-----------------------------------------------------------
Unable to handle kernel NULL pointer dereference at virtual
address 000001ac
...
Internal error: Oops: 17 [#1] SMP ARM
...
Hardware name: STi SoC with Flattened Device Tree
task: c0c05e80 task.stack: c0c00000
PC is at dwmac4_wrback_get_tx_timestamp_status+0x0/0xc
LR is at stmmac_tx_clean+0x2f8/0x4d4
-----------------------------------------------------------
In case of GMAC4 the extended descriptor pointers were
used for getting the timestamp. These are NULL for this HW,
and the normal ones must be used.
The PTP also had problems on this chip due to the bad
register management and issues on the algo adopted to
setup the PTP and getting the timestamp values from the
descriptors.
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Acked-by: Rayagond Kokatanur <rayagond@vayavyalabs.com>
Acked-by: Alexandre TORGUE <alexandre.torgue@st.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c')
-rw-r--r-- | drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c | 68 |
1 files changed, 57 insertions, 11 deletions
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c b/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c index a1b17cd7886b..2ef2f0c03e76 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac4_descs.c @@ -204,14 +204,18 @@ static void dwmac4_rd_enable_tx_timestamp(struct dma_desc *p) static int dwmac4_wrback_get_tx_timestamp_status(struct dma_desc *p) { - return (p->des3 & TDES3_TIMESTAMP_STATUS) - >> TDES3_TIMESTAMP_STATUS_SHIFT; + /* Context type from W/B descriptor must be zero */ + if (p->des3 & TDES3_CONTEXT_TYPE) + return -EINVAL; + + /* Tx Timestamp Status is 1 so des0 and des1'll have valid values */ + if (p->des3 & TDES3_TIMESTAMP_STATUS) + return 0; + + return 1; } -/* NOTE: For RX CTX bit has to be checked before - * HAVE a specific function for TX and another one for RX - */ -static u64 dwmac4_wrback_get_timestamp(void *desc, u32 ats) +static inline u64 dwmac4_get_timestamp(void *desc, u32 ats) { struct dma_desc *p = (struct dma_desc *)desc; u64 ns; @@ -223,12 +227,54 @@ static u64 dwmac4_wrback_get_timestamp(void *desc, u32 ats) return ns; } -static int dwmac4_context_get_rx_timestamp_status(void *desc, u32 ats) +static int dwmac4_rx_check_timestamp(void *desc) +{ + struct dma_desc *p = (struct dma_desc *)desc; + u32 own, ctxt; + int ret = 1; + + own = p->des3 & RDES3_OWN; + ctxt = ((p->des3 & RDES3_CONTEXT_DESCRIPTOR) + >> RDES3_CONTEXT_DESCRIPTOR_SHIFT); + + if (likely(!own && ctxt)) { + if ((p->des0 == 0xffffffff) && (p->des1 == 0xffffffff)) + /* Corrupted value */ + ret = -EINVAL; + else + /* A valid Timestamp is ready to be read */ + ret = 0; + } + + /* Timestamp not ready */ + return ret; +} + +static int dwmac4_wrback_get_rx_timestamp_status(void *desc, u32 ats) { struct dma_desc *p = (struct dma_desc *)desc; + int ret = -EINVAL; + + /* Get the status from normal w/b descriptor */ + if (likely(p->des3 & TDES3_RS1V)) { + if (likely(p->des1 & RDES1_TIMESTAMP_AVAILABLE)) { + int i = 0; + + /* Check if timestamp is OK from context descriptor */ + do { + ret = dwmac4_rx_check_timestamp(desc); + if (ret < 0) + goto exit; + i++; - return (p->des1 & RDES1_TIMESTAMP_AVAILABLE) - >> RDES1_TIMESTAMP_AVAILABLE_SHIFT; + } while ((ret == 1) || (i < 10)); + + if (i == 10) + ret = -EBUSY; + } + } +exit: + return ret; } static void dwmac4_rd_init_rx_desc(struct dma_desc *p, int disable_rx_ic, @@ -373,8 +419,8 @@ const struct stmmac_desc_ops dwmac4_desc_ops = { .get_rx_frame_len = dwmac4_wrback_get_rx_frame_len, .enable_tx_timestamp = dwmac4_rd_enable_tx_timestamp, .get_tx_timestamp_status = dwmac4_wrback_get_tx_timestamp_status, - .get_timestamp = dwmac4_wrback_get_timestamp, - .get_rx_timestamp_status = dwmac4_context_get_rx_timestamp_status, + .get_rx_timestamp_status = dwmac4_wrback_get_rx_timestamp_status, + .get_timestamp = dwmac4_get_timestamp, .set_tx_ic = dwmac4_rd_set_tx_ic, .prepare_tx_desc = dwmac4_rd_prepare_tx_desc, .prepare_tso_tx_desc = dwmac4_rd_prepare_tso_tx_desc, |