| Message ID | 1551504025-3541-2-git-send-email-skomatineni@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [V1,01/11] mmc: tegra: fix ddr signaling for non-ddr modes | expand |
On 2/03/19 7:20 AM, Sowjanya Komatineni wrote: > As per the Host Controller Standard Specification Version 4.20, > limitation of tuning iteration count is removed as PLL locking > time can be longer than UHS-1 tuning due to larger PVT fluctuation > and it will result in increase of tuning iteration to complete the > tuning. > > This patch creates a hook get_max_tuning_loop_count to allow hosts > to specify maximum tuning iterations and updates execute_tuning > to use the specified maximum tuning iteration count. > > Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com> > --- > drivers/mmc/host/sdhci.c | 7 +++++-- > drivers/mmc/host/sdhci.h | 1 + > 2 files changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c > index a8141ff9be03..e9e919218006 100644 > --- a/drivers/mmc/host/sdhci.c > +++ b/drivers/mmc/host/sdhci.c > @@ -2366,12 +2366,15 @@ EXPORT_SYMBOL_GPL(sdhci_send_tuning); > static int __sdhci_execute_tuning(struct sdhci_host *host, u32 opcode) > { > int i; > + int tuning_loop_count = MAX_TUNING_LOOP; > > + if (host->ops->get_max_tuning_loop_count) > + tuning_loop_count = host->ops->get_max_tuning_loop_count(host); I would prefer to make tuning_loop_count a sdhci_host member initialized to MAX_TUNING_LOOP in sdhci_alloc_host(). Then hook .execute_tuning e.g. host->mmc_host_ops.execute_tuning = tegra_sdhci_execute_tuning; and set up host->tuning_loop_count > /* > * Issue opcode repeatedly till Execute Tuning is set to 0 or the number > - * of loops reaches 40 times. > + * of loops reaches tuning loop count. > */ > - for (i = 0; i < MAX_TUNING_LOOP; i++) { > + for (i = 0; i < tuning_loop_count; i++) { > u16 ctrl; > > sdhci_send_tuning(host, opcode); > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h > index 01002cba1359..c80e0d6f9b10 100644 > --- a/drivers/mmc/host/sdhci.h > +++ b/drivers/mmc/host/sdhci.h > @@ -638,6 +638,7 @@ struct sdhci_ops { > unsigned int (*get_ro)(struct sdhci_host *host); > void (*reset)(struct sdhci_host *host, u8 mask); > int (*platform_execute_tuning)(struct sdhci_host *host, u32 opcode); > + int (*get_max_tuning_loop_count)(struct sdhci_host *host); > void (*set_uhs_signaling)(struct sdhci_host *host, unsigned int uhs); > void (*hw_reset)(struct sdhci_host *host); > void (*adma_workaround)(struct sdhci_host *host, u32 intmask); >
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index a8141ff9be03..e9e919218006 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -2366,12 +2366,15 @@ EXPORT_SYMBOL_GPL(sdhci_send_tuning); static int __sdhci_execute_tuning(struct sdhci_host *host, u32 opcode) { int i; + int tuning_loop_count = MAX_TUNING_LOOP; + if (host->ops->get_max_tuning_loop_count) + tuning_loop_count = host->ops->get_max_tuning_loop_count(host); /* * Issue opcode repeatedly till Execute Tuning is set to 0 or the number - * of loops reaches 40 times. + * of loops reaches tuning loop count. */ - for (i = 0; i < MAX_TUNING_LOOP; i++) { + for (i = 0; i < tuning_loop_count; i++) { u16 ctrl; sdhci_send_tuning(host, opcode); diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h index 01002cba1359..c80e0d6f9b10 100644 --- a/drivers/mmc/host/sdhci.h +++ b/drivers/mmc/host/sdhci.h @@ -638,6 +638,7 @@ struct sdhci_ops { unsigned int (*get_ro)(struct sdhci_host *host); void (*reset)(struct sdhci_host *host, u8 mask); int (*platform_execute_tuning)(struct sdhci_host *host, u32 opcode); + int (*get_max_tuning_loop_count)(struct sdhci_host *host); void (*set_uhs_signaling)(struct sdhci_host *host, unsigned int uhs); void (*hw_reset)(struct sdhci_host *host); void (*adma_workaround)(struct sdhci_host *host, u32 intmask);
As per the Host Controller Standard Specification Version 4.20, limitation of tuning iteration count is removed as PLL locking time can be longer than UHS-1 tuning due to larger PVT fluctuation and it will result in increase of tuning iteration to complete the tuning. This patch creates a hook get_max_tuning_loop_count to allow hosts to specify maximum tuning iterations and updates execute_tuning to use the specified maximum tuning iteration count. Signed-off-by: Sowjanya Komatineni <skomatineni@nvidia.com> --- drivers/mmc/host/sdhci.c | 7 +++++-- drivers/mmc/host/sdhci.h | 1 + 2 files changed, 6 insertions(+), 2 deletions(-)