Implement errata handling to use flags instead of cpu_is_* and cpu_class_* in the code. The errata flags are initialized at init time and during runtime we are using the errata variable (via the IS_DMA_ERRATA macro) to execute the required errata workaround. Reused errata handling patch from Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx> https://patchwork.kernel.org/patch/231191/ Signed-off-by: G, Manjunath Kondaiah <manjugk@xxxxxx> Cc: Peter Ujfalusi <peter.ujfalusi@xxxxxxxxx> Cc: Benoit Cousson <b-cousson@xxxxxx> Cc: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx> Cc: Santosh Shilimkar <santosh.shilimkar@xxxxxx> --- arch/arm/plat-omap/dma.c | 134 ++++++++++++++++++++++---------- arch/arm/plat-omap/include/plat/dma.h | 11 +++ 2 files changed, 103 insertions(+), 42 deletions(-) diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c index bb54be3..0e1c7b4 100644 --- a/arch/arm/plat-omap/dma.c +++ b/arch/arm/plat-omap/dma.c @@ -195,6 +195,7 @@ enum { DMA_CHAIN_STARTED, DMA_CHAIN_NOTSTARTED }; #define OMAP_FUNC_MUX_ARM_BASE (0xfffe1000 + 0xec) static int enable_1510_mode; +static u32 errata; static struct omap_dma_global_context_registers { u32 dma_irqenable_l0; @@ -1216,12 +1217,8 @@ void omap_start_dma(int lch) cur_lch = next_lch; } while (next_lch != -1); - } else if (cpu_is_omap242x() || - (cpu_is_omap243x() && omap_type() <= OMAP2430_REV_ES1_0)) { - - /* Errata: Need to write lch even if not using chaining */ + } else if (IS_DMA_ERRATA(DMA_ERRATA_PARALLEL_CHANNELS)) dma_write(lch, CLNK_CTRL2, lch); - } omap_enable_channel_irq(lch); @@ -1231,17 +1228,8 @@ void omap_start_dma(int lch) dma_write(l, CCR1, lch); } else { l = dma_read(CCR2, lch); - /* - * Errata: Inter Frame DMA buffering issue (All OMAP2420 and - * OMAP2430ES1.0): DMA will wrongly buffer elements if packing - * and bursting is enabled. This might result in data gets - * stalled in FIFO at the end of the block. - * Workaround: DMA channels must have BUFFERING_DISABLED bit - * set to guarantee no data will stay in the DMA FIFO in case - * inter frame buffering occurs. - */ - if (cpu_is_omap2420() || (cpu_is_omap2430() && - (omap_type() == OMAP2430_REV_ES1_0))) + + if (IS_DMA_ERRATA(DMA_ERRATA_IFRAME_BUFFERING)) l |= OMAP_DMA_CCR_BUFFERING_DISABLE; l |= OMAP_DMA_CCR_EN; @@ -1253,14 +1241,14 @@ EXPORT_SYMBOL(omap_start_dma); void omap_stop_dma(int lch) { - u32 l; + u32 l = 0; /* Disable all interrupts on the channel */ if (cpu_class_is_omap1()) dma_write(0, CICR1, lch); - /* OMAP3 Errata i541: sDMA FIFO draining does not finish */ - if (cpu_is_omap34xx() && (l & OMAP_DMA_CCR_SEL_SRC_DST_SYNC)) { + if (IS_DMA_ERRATA(DMA_ERRATA_i541) && + (l & OMAP_DMA_CCR_SEL_SRC_DST_SYNC)) { int i = 0; u32 sys_cf; @@ -1367,11 +1355,7 @@ dma_addr_t omap_get_dma_src_pos(int lch) else offset = dma_read(CSAC2, lch); - /* - * omap 3.2/3.3 erratum: sometimes 0 is returned if CSAC/CDAC is - * read before the DMA controller finished disabling the channel. - */ - if (!cpu_is_omap15xx() && offset == 0) { + if (IS_DMA_ERRATA(DMA_ERRATA_3_3) && offset == 0) { if (cpu_class_is_omap1()) offset = dma_read(CSAC1, lch); else @@ -1966,7 +1950,7 @@ int omap_stop_dma_chain_transfers(int chain_id) { int *channels; u32 l, i; - u32 sys_cf; + u32 sys_cf = 0; /* Check for input params */ if (unlikely((chain_id < 0 || chain_id >= dma_lch_count))) { @@ -1981,15 +1965,13 @@ int omap_stop_dma_chain_transfers(int chain_id) } channels = dma_linked_lch[chain_id].linked_dmach_q; - /* - * DMA Errata: - * Special programming model needed to disable DMA before end of block - */ - sys_cf = dma_read(OCP_SYSCONFIG, 0); - l = sys_cf; - /* Middle mode reg set no Standby */ - l &= ~((1 << 12)|(1 << 13)); - dma_write(l, OCP_SYSCONFIG, 0); + if (IS_DMA_ERRATA(DMA_ERRATA_i88)) { + sys_cf = dma_read(OCP_SYSCONFIG, 0); + l = sys_cf; + /* Middle mode reg set no Standby */ + l &= ~((1 << 12)|(1 << 13)); + dma_write(l, OCP_SYSCONFIG, 0); + } for (i = 0; i < dma_linked_lch[chain_id].no_of_lchs_linked; i++) { @@ -2008,8 +1990,8 @@ int omap_stop_dma_chain_transfers(int chain_id) /* Reset the Queue pointers */ OMAP_DMA_CHAIN_QINIT(chain_id); - /* Errata - put in the old value */ - dma_write(sys_cf, OCP_SYSCONFIG, 0); + if (IS_DMA_ERRATA(DMA_ERRATA_i88)) + dma_write(sys_cf, OCP_SYSCONFIG, 0); return 0; } @@ -2215,12 +2197,7 @@ static int omap2_dma_handle_ch(int ch) if (unlikely(status & OMAP2_DMA_TRANS_ERR_IRQ)) { printk(KERN_INFO "DMA transaction error with device %d\n", dma_chan[ch].dev_id); - if (cpu_class_is_omap2()) { - /* - * Errata: sDMA Channel is not disabled - * after a transaction error. So we explicitely - * disable the channel - */ + if (IS_DMA_ERRATA(DMA_ERRATA_i378)) { u32 ccr; ccr = dma_read(CCR2, ch); @@ -2334,6 +2311,76 @@ void omap_dma_global_context_restore(void) omap_clear_dma(ch); } +static void configure_dma_errata(void) +{ + + /* + * Erratas applicable for OMAP2430ES1.0 and all omap2420 + * + * I. + * Errata ID: XX Inter Frame DMA buffering issue DMA will wrongly + * buffer elements if packing and bursting is enabled. This might + * result in data gets stalled in FIFO at the end of the block. + * Workaround: DMA channels must have BUFFERING_DISABLED bit set to + * guarantee no data will stay in the DMA FIFO in case inter frame + * buffering occurs + * + * II. + * Errata ID: XX DMA may hang when several channels are used in parallel + * In the following configuration, DMA channel hanging can occur: + * a. Channel i, hardware synchronized, is enabled + * b. Another channel (Channel x), software synchronized, is enabled. + * c. Channel i is disabled before end of transfer + * d. Channel i is reenabled. + * e. Steps 1 to 4 are repeated a certain number of times. + * f. A third channel (Channel y), software synchronized, is enabled. + * Channel x and Channel y may hang immediately after step 'f'. + * Workaround: + * For any channel used - make sure NextLCH_ID is set to the value j. + */ + if (cpu_is_omap2420() || (cpu_is_omap2430() && + (omap_type() == OMAP2430_REV_ES1_0))) { + + SET_DMA_ERRATA(DMA_ERRATA_IFRAME_BUFFERING); + SET_DMA_ERRATA(DMA_ERRATA_PARALLEL_CHANNELS); + } + + /* + * Errata ID: i378: OMAP2plus: sDMA Channel is not disabled + * after a transaction error. + * Workaround: SW should explicitely disable the channel. + */ + if (cpu_class_is_omap2()) + SET_DMA_ERRATA(DMA_ERRATA_i378); + + /* + * Errata ID: i541: sDMA FIFO draining does not finish + * If sDMA channel is disabled on the fly, sDMA enters standby even + * through FIFO Drain is still in progress + * Workaround: Put sDMA in NoStandby more before a logical channel is + * disabled, then put it back to SmartStandby right after the channel + * finishes FIFO draining. + */ + if (cpu_is_omap34xx()) + SET_DMA_ERRATA(DMA_ERRATA_i541); + + /* + * Errata ID: i88 : Special programming model needed to disable DMA + * before end of block. + * Workaround: software must ensure that the DMA is configured in No + * Standby mode(DMAx_OCP_SYSCONFIG.MIDLEMODE = "01") + */ + if (omap_type() == OMAP3430_REV_ES1_0) + SET_DMA_ERRATA(DMA_ERRATA_i88); + + /* + * Errata 3.2/3.3: sometimes 0 is returned if CSAC/CDAC is + * read before the DMA controller finished disabling the channel. + */ + if (!cpu_is_omap15xx()) + SET_DMA_ERRATA(DMA_ERRATA_3_3); +} + /*----------------------------------------------------------------------------*/ static int __init omap_init_dma(void) @@ -2483,6 +2530,9 @@ static int __init omap_init_dma(void) } } + /* Configure errata handling for all omap's */ + configure_dma_errata(); + return 0; out_free: diff --git a/arch/arm/plat-omap/include/plat/dma.h b/arch/arm/plat-omap/include/plat/dma.h index 27578f3..5e28d26 100644 --- a/arch/arm/plat-omap/include/plat/dma.h +++ b/arch/arm/plat-omap/include/plat/dma.h @@ -285,6 +285,17 @@ #define DMA_CH_PRIO_HIGH 0x1 #define DMA_CH_PRIO_LOW 0x0 /* Def */ +/* Errata handling */ +#define IS_DMA_ERRATA(id) (errata &= (id)) +#define SET_DMA_ERRATA(id) (errata |= (id)) + +#define DMA_ERRATA_IFRAME_BUFFERING (1 << 0) +#define DMA_ERRATA_PARALLEL_CHANNELS (1 << 1) +#define DMA_ERRATA_i378 (1 << 2) +#define DMA_ERRATA_i541 (1 << 3) +#define DMA_ERRATA_i88 (1 << 4) +#define DMA_ERRATA_3_3 (1 << 5) + enum omap_dma_burst_mode { OMAP_DMA_DATA_BURST_DIS = 0, OMAP_DMA_DATA_BURST_4, -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
