Messages in this thread | | | Subject | Re: [PATCH V2 2/2] mmc: mmci: add variant property to send stop cmd if a command fail | From | Ludovic BARRE <> | Date | Thu, 22 Nov 2018 11:14:53 +0100 |
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hi Ulf
due to some ST internal works, I will busy the next days. But I will sent the change as soon as possible.
On 11/21/18 6:56 PM, Ulf Hansson wrote: > On 7 November 2018 at 10:30, Ludovic Barre <ludovic.Barre@st.com> wrote: >> From: Ludovic Barre <ludovic.barre@st.com> >> >> The mmc framework follows the requirement of SD_Specification: >> the STOP_TRANSMISSION is sent on multiple write/read commands >> and the stop command (alone), not needed on other ADTC commands. >> >> But, if an error happens on command or data transmission, some >> variants require a stop command "STOP_TRANSMISION" to clear the DPSM >> "Data Path State Machine". If it's not done the next data >> command freezes hardware block. >> Needed to support the STM32 sdmmc variant. > > May I suggest some re-wording of this changelog, as to make it more > clear of why this is needed. Something along the lines of: > > "The current approach with sending a CMD12 (STOP_TRANSMISSION) to > complete a data transfer request, either because of using the open > ended transmission type or because of receiving an error during a data > transfer, isn't sufficient for the STM32 sdmmc variant. > > More precisely, for STM32 sdmmc the DPSM ("Data Path State Machine" ) > needs to be cleared by sending a CMD12, also for the so called ADTC > commands. For this reason, add a new mmci variant property and let the > driver send a CMD12 to complete ADTC commands, in case it's set."
I will change, it's more accurate and concise, thanks for re-wording
> >> >> Signed-off-by: Ludovic Barre <ludovic.barre@st.com> >> --- >> drivers/mmc/host/mmci.c | 33 +++++++++++++++++++++++++++++++++ >> drivers/mmc/host/mmci.h | 4 ++++ >> 2 files changed, 37 insertions(+) >> >> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c >> index 13fa640..47b865d 100644 >> --- a/drivers/mmc/host/mmci.c >> +++ b/drivers/mmc/host/mmci.c >> @@ -21,6 +21,7 @@ >> #include <linux/err.h> >> #include <linux/highmem.h> >> #include <linux/log2.h> >> +#include <linux/mmc/mmc.h> >> #include <linux/mmc/pm.h> >> #include <linux/mmc/host.h> >> #include <linux/mmc/card.h> >> @@ -57,6 +58,8 @@ void sdmmc_variant_init(struct mmci_host *host); >> #else >> static inline void sdmmc_variant_init(struct mmci_host *host) {} >> #endif >> +static void >> +mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c); >> >> static unsigned int fmax = 515633; >> >> @@ -274,6 +277,7 @@ static struct variant_data variant_stm32_sdmmc = { >> .cmdreg_lrsp_crc = MCI_CPSM_STM32_LRSP_CRC, >> .cmdreg_srsp_crc = MCI_CPSM_STM32_SRSP_CRC, >> .cmdreg_srsp = MCI_CPSM_STM32_SRSP, >> + .cmdreg_stop = MCI_CPSM_STM32_CMDSTOP, >> .data_cmd_enable = MCI_CPSM_STM32_CMDTRANS, >> .irq_pio_mask = MCI_IRQ_PIO_STM32_MASK, >> .datactrl_first = true, >> @@ -573,6 +577,24 @@ void mmci_dma_error(struct mmci_host *host) >> static void >> mmci_request_end(struct mmci_host *host, struct mmc_request *mrq) >> { >> + /* >> + * If an error happens on command or data transmission, some variants >> + * require a stop command to reinit the DPSM. >> + * If it's not done the next data command freeze hardware block. >> + */ >> + if (host->variant->cmdreg_stop) { >> + u32 dpsm; >> + >> + dpsm = readl_relaxed(host->base + MMCISTATUS); >> + dpsm &= MCI_STM32_DPSMACTIVE; >> + >> + if (dpsm && ((mrq->cmd && mrq->cmd->error) || >> + (mrq->data && mrq->data->error))) { >> + mmci_start_command(host, &host->stop_abort, 0); >> + return; >> + } > > I would rather move this code to a separate function.
OK
Also, I think > you need something else (or additional) than polling the MMCISTATUS > register, as in principle you could end up sending CMD12 several times > for the same request, which isn't correct.
In mmci_request_end, if the DPSM is still enabled, there was no previous "cmd12" sent. So Normally, the regular and special cmd12 can't be sent for the same request.
> > To me the best solution would probably be to make use of the > host->data pointer, as it becomes set when DPSM has been enabled. > However, host->data is also cleared in mmci_stop_data() which is being > called prior mmci_request_end(). In other words, we need to figure > under what conditions the new code above should be triggered/called > and then also change the conditions for when mmci_request_end() shall > be called. > > In principle look at callers of mmci_request_end() and > mmci_stop_data() and update those paths. > >> + } >> + >> writel(0, host->base + MMCICOMMAND); >> >> BUG_ON(host->data); >> @@ -1100,6 +1122,10 @@ mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c) >> mmci_reg_delay(host); >> } >> >> + if (host->variant->cmdreg_stop && >> + cmd->opcode == MMC_STOP_TRANSMISSION) >> + c |= host->variant->cmdreg_stop; >> + > > Hmm. > > It looks like the above changes, together with the introduction of the > variant property, belongs in a separate patch, preceding $subject > patch in the series. > > The reason is, that to me, it makes sense to add the special treatment > of the ADTC commands in a separate patch. Can you please split it up > and then of course update the change log accordingly!?
Ok, I will split this part in separate patch.
> >> c |= cmd->opcode | host->variant->cmdreg_cpsm_enable; >> if (cmd->flags & MMC_RSP_PRESENT) { >> if (cmd->flags & MMC_RSP_136) >> @@ -1950,6 +1976,13 @@ static int mmci_probe(struct amba_device *dev, >> mmc->max_busy_timeout = 0; >> } >> >> + /* prepare the stop command, used to abort and reinitialized the DPSM */ >> + if (variant->cmdreg_stop) { >> + host->stop_abort.opcode = MMC_STOP_TRANSMISSION; >> + host->stop_abort.arg = 0; >> + host->stop_abort.flags = MMC_RSP_R1B | MMC_CMD_AC; >> + } >> + >> mmc->ops = &mmci_ops; >> >> /* We support these PM capabilities. */ >> diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h >> index 550dd39..35372cd 100644 >> --- a/drivers/mmc/host/mmci.h >> +++ b/drivers/mmc/host/mmci.h >> @@ -161,6 +161,7 @@ >> #define MCI_ST_CEATAEND (1 << 23) >> #define MCI_ST_CARDBUSY (1 << 24) >> /* Extended status bits for the STM32 variants */ >> +#define MCI_STM32_DPSMACTIVE BIT(12) >> #define MCI_STM32_BUSYD0 BIT(20) >> >> #define MMCICLEAR 0x038 >> @@ -264,6 +265,7 @@ struct mmci_host; >> * @cmdreg_lrsp_crc: enable value for long response with crc >> * @cmdreg_srsp_crc: enable value for short response with crc >> * @cmdreg_srsp: enable value for short response without crc >> + * @cmdreg_stop: enable value for stop and abort transmission >> * @datalength_bits: number of bits in the MMCIDATALENGTH register >> * @fifosize: number of bytes that can be written when MMCI_TXFIFOEMPTY >> * is asserted (likewise for RX) >> @@ -316,6 +318,7 @@ struct variant_data { >> unsigned int cmdreg_lrsp_crc; >> unsigned int cmdreg_srsp_crc; >> unsigned int cmdreg_srsp; >> + unsigned int cmdreg_stop; >> unsigned int datalength_bits; >> unsigned int fifosize; >> unsigned int fifohalfsize; >> @@ -375,6 +378,7 @@ struct mmci_host { >> void __iomem *base; >> struct mmc_request *mrq; >> struct mmc_command *cmd; >> + struct mmc_command stop_abort; >> struct mmc_data *data; >> struct mmc_host *mmc; >> struct clk *clk; >> -- >> 2.7.4 >> > > Kind regards > Uffe >
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