On Fri, Aug 17, 2012 at 9:35 PM, Semen Protsenko <[email protected]> wrote:
> Errata description:
> Due to a bad behavior of an internal signal, the Card Error interrupt bit
> MMCHS_STAT[28] CERR may not be set sometimes when an error occurred in the
> card response.
>
> Workaround:
> After responses of type R1/R1b for all cards and responses of type R5/R5b/R6
> for SD and SDIO cards, software must read two registers: MMCHS_RSP10 and
> MMCHS_CSRE. When a MMCHS_CSRE[i] bit is set to 1, if the corresponding bit at
> the same position in the response MMCHS_RSP10[i] is set to 1, the host
> controller indicates a card error and software should proceed in the same way
> as if a CERR interrupt would have been detected in the MMCHS_STAT register.
>
> Note:
> This errata is applicable for omap44xx.
>
> Signed-off-by: Semen Protsenko <[email protected]>
The implementation looks fine, but can we simply not set the errata
flag and make this as default
behaviour ? I suppose the documented behaviour with CSRE and RSP10 is
independent of the
errata..
Also, please send it to the linux-mmc list as well.
> ---
> drivers/mmc/host/omap_hsmmc.c | 38 ++++++++++++++++++++++++++++++++++++++
> 1 file changed, 38 insertions(+)
>
> diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
> index 3a09f93..17803de 100644
> --- a/drivers/mmc/host/omap_hsmmc.c
> +++ b/drivers/mmc/host/omap_hsmmc.c
> @@ -34,6 +34,7 @@
> #include <linux/mmc/host.h>
> #include <linux/mmc/core.h>
> #include <linux/mmc/mmc.h>
> +#include <linux/mmc/card.h>
> #include <linux/io.h>
> #include <linux/semaphore.h>
> #include <linux/gpio.h>
> @@ -47,6 +48,7 @@
> /* OMAP HSMMC Host Controller Registers */
> #define OMAP_HSMMC_SYSCONFIG 0x0010
> #define OMAP_HSMMC_SYSSTATUS 0x0014
> +#define OMAP_HSMMC_CSRE 0x0024
> #define OMAP_HSMMC_CON 0x002C
> #define OMAP_HSMMC_BLK 0x0104
> #define OMAP_HSMMC_ARG 0x0108
> @@ -117,6 +119,9 @@
> #define OMAP_MMC_MAX_CLOCK 52000000
> #define DRIVER_NAME "omap_hsmmc"
>
> +/* Errata definitions */
> +#define OMAP_HSMMC_ERRATA_I761 BIT(0)
> +
> /*
> * One controller can have multiple slots, like on some omap boards using
> * omap.c controller driver. Luckily this is not currently done on any known
> @@ -177,6 +182,7 @@ struct omap_hsmmc_host {
> int reqs_blocked;
> int use_reg;
> int req_in_progress;
> + unsigned int errata;
> struct omap_hsmmc_next next_data;
>
> struct omap_mmc_platform_data *pdata;
> @@ -857,6 +863,23 @@ omap_hsmmc_xfer_done(struct omap_hsmmc_host *host,
> struct mmc_data *data)
> omap_hsmmc_start_command(host, data->stop, NULL);
> }
>
> +static int
> +omap_hsmmc_errata_i761(struct omap_hsmmc_host *host, struct mmc_command *cmd)
> +{
> + u32 rsp10, csre;
> +
> + if ((cmd->flags & MMC_RSP_R1) == MMC_RSP_R1
> + || (host->mmc->card && (mmc_card_sd(host->mmc->card)
> + || mmc_card_sdio(host->mmc->card))
> + && (cmd->flags & MMC_RSP_R5))) {
> + rsp10 = OMAP_HSMMC_READ(host->base, RSP10);
> + csre = OMAP_HSMMC_READ(host->base, CSRE);
> + return rsp10 & csre;
> + }
> +
> + return 0;
> +}
> +
> /*
> * Notify the core about command completion
> */
> @@ -1046,6 +1069,17 @@ static void omap_hsmmc_do_irq(struct omap_hsmmc_host
> *host, int status)
> }
> }
>
> + /* Errata i761 */
> + if ((host->errata & OMAP_HSMMC_ERRATA_I761) && host->cmd
> + && omap_hsmmc_errata_i761(host, host->cmd)) {
> + /* Do the same as for CARD_ERR case */
> + dev_dbg(mmc_dev(host->mmc), "Ignoring card err CMD%d\n",
> + host->cmd->opcode);
> + end_cmd = 1;
> + if (host->data)
> + end_trans = 1;
> + }
> +
> OMAP_HSMMC_WRITE(host->base, STAT, status);
>
> if (end_cmd || ((status & CC) && host->cmd))
> @@ -1829,6 +1863,10 @@ static int __devinit omap_hsmmc_probe(struct
> platform_device *pdev)
> host->power_mode = MMC_POWER_OFF;
> host->next_data.cookie = 1;
>
> + host->errata = 0;
> + if (cpu_is_omap44xx())
> + host->errata |= OMAP_HSMMC_ERRATA_I761;
> +
> platform_set_drvdata(pdev, host);
>
> mmc->ops = &omap_hsmmc_ops;
> --
> 1.7.10.4
>
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