@@ -158,6 +158,8 @@ struct dma_desc {
u32 buffer2_size:13;
u32 reserved4:3;
} etx; /* -- enhanced -- */
+
+ u64 all_flags;
} des01;
unsigned int des2;
unsigned int des3;
@@ -240,6 +240,7 @@ static int enh_desc_get_rx_status(void *data, struct stmmac_extra_stats *x,
static void enh_desc_init_rx_desc(struct dma_desc *p, int disable_rx_ic,
int mode, int end)
{
+ p->des01.all_flags = 0;
p->des01.erx.own = 1;
p->des01.erx.buffer1_size = BUF_SIZE_8KiB - 1;
@@ -254,7 +255,7 @@ static void enh_desc_init_rx_desc(struct dma_desc *p, int disable_rx_ic,
static void enh_desc_init_tx_desc(struct dma_desc *p, int mode, int end)
{
- p->des01.etx.own = 0;
+ p->des01.all_flags = 0;
if (mode == STMMAC_CHAIN_MODE)
ehn_desc_tx_set_on_chain(p, end);
else
@@ -123,6 +123,7 @@ static int ndesc_get_rx_status(void *data, struct stmmac_extra_stats *x,
static void ndesc_init_rx_desc(struct dma_desc *p, int disable_rx_ic, int mode,
int end)
{
+ p->des01.all_flags = 0;
p->des01.rx.own = 1;
p->des01.rx.buffer1_size = BUF_SIZE_2KiB - 1;
@@ -137,7 +138,7 @@ static void ndesc_init_rx_desc(struct dma_desc *p, int disable_rx_ic, int mode,
static void ndesc_init_tx_desc(struct dma_desc *p, int mode, int end)
{
- p->des01.tx.own = 0;
+ p->des01.all_flags = 0;
if (mode == STMMAC_CHAIN_MODE)
ndesc_tx_set_on_chain(p, end);
else
@@ -1188,41 +1188,41 @@ static int alloc_dma_desc_resources(struct stmmac_priv *priv)
goto err_tx_skbuff;
if (priv->extend_desc) {
- priv->dma_erx = dma_alloc_coherent(priv->device, rxsize *
- sizeof(struct
- dma_extended_desc),
- &priv->dma_rx_phy,
- GFP_KERNEL);
+ priv->dma_erx = dma_zalloc_coherent(priv->device, rxsize *
+ sizeof(struct
+ dma_extended_desc),
+ &priv->dma_rx_phy,
+ GFP_KERNEL);
if (!priv->dma_erx)
goto err_dma;
- priv->dma_etx = dma_alloc_coherent(priv->device, txsize *
- sizeof(struct
- dma_extended_desc),
- &priv->dma_tx_phy,
- GFP_KERNEL);
+ priv->dma_etx = dma_zalloc_coherent(priv->device, txsize *
+ sizeof(struct
+ dma_extended_desc),
+ &priv->dma_tx_phy,
+ GFP_KERNEL);
if (!priv->dma_etx) {
dma_free_coherent(priv->device, priv->dma_rx_size *
- sizeof(struct dma_extended_desc),
- priv->dma_erx, priv->dma_rx_phy);
+ sizeof(struct dma_extended_desc),
+ priv->dma_erx, priv->dma_rx_phy);
goto err_dma;
}
} else {
- priv->dma_rx = dma_alloc_coherent(priv->device, rxsize *
- sizeof(struct dma_desc),
- &priv->dma_rx_phy,
- GFP_KERNEL);
+ priv->dma_rx = dma_zalloc_coherent(priv->device, rxsize *
+ sizeof(struct dma_desc),
+ &priv->dma_rx_phy,
+ GFP_KERNEL);
if (!priv->dma_rx)
goto err_dma;
- priv->dma_tx = dma_alloc_coherent(priv->device, txsize *
- sizeof(struct dma_desc),
- &priv->dma_tx_phy,
- GFP_KERNEL);
+ priv->dma_tx = dma_zalloc_coherent(priv->device, txsize *
+ sizeof(struct dma_desc),
+ &priv->dma_tx_phy,
+ GFP_KERNEL);
if (!priv->dma_tx) {
dma_free_coherent(priv->device, priv->dma_rx_size *
- sizeof(struct dma_desc),
- priv->dma_rx, priv->dma_rx_phy);
+ sizeof(struct dma_desc),
+ priv->dma_rx, priv->dma_rx_phy);
goto err_dma;
}
}
This is a note to let you know that I have just added a patch titled stmmac: troubleshoot unexpected bits in des0 & des1 to the linux-3.19.y-queue branch of the 3.19.y-ckt extended stable tree which can be found at: http://kernel.ubuntu.com/git/ubuntu/linux.git/log/?h=linux-3.19.y-queue This patch is scheduled to be released in version 3.19.y-ckt4. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.19.y-ckt tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From 1fce7e462a5f1996389629d10353110869e45035 Mon Sep 17 00:00:00 2001 From: Alexey Brodkin <Alexey.Brodkin@synopsys.com> Date: Wed, 24 Jun 2015 11:47:41 +0300 Subject: stmmac: troubleshoot unexpected bits in des0 & des1 commit f1590670ce069eefeb93916391a67643e6ad1630 upstream. Current implementation of descriptor init procedure only takes care about setting/clearing ownership flag in "des0"/"des1" fields while it is perfectly possible to get unexpected bits set because of the following factors: [1] On driver probe underlying memory allocated with dma_alloc_coherent() might not be zeroed and so it will be filled with garbage. [2] During driver operation some bits could be set by SD/MMC controller (for example error flags etc). And unexpected and/or randomly set flags in "des0"/"des1" fields may lead to unpredictable behavior of GMAC DMA block. This change addresses both items above with: [1] Use of dma_zalloc_coherent() instead of simple dma_alloc_coherent() to make sure allocated memory is zeroed. That shouldn't affect performance because this allocation only happens once on driver probe. [2] Do explicit zeroing of both "des0" and "des1" fields of all buffer descriptors during initialization of DMA transfer. And while at it fixed identation of dma_free_coherent() counterpart as well. Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com> Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com> Cc: arc-linux-dev@synopsys.com Cc: linux-kernel@vger.kernel.org Cc: David Miller <davem@davemloft.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/net/ethernet/stmicro/stmmac/descs.h | 2 ++ drivers/net/ethernet/stmicro/stmmac/enh_desc.c | 3 +- drivers/net/ethernet/stmicro/stmmac/norm_desc.c | 3 +- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 44 +++++++++++------------ 4 files changed, 28 insertions(+), 24 deletions(-) -- 1.9.1