From 1d8cd065f7ab2992903f4611d8400ee794de0699 Mon Sep 17 00:00:00 2001 From: Sowjanya Komatineni Date: Sat, 23 Mar 2019 21:45:19 -0700 Subject: [PATCH] mmc: sdhci: allow host to specify maximum tuning loops 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 sdhci_host member tuning_loop_count to allow hosts to specify maximum tuning iterations and also updates execute_tuning to use this specified maximum tuning iteration count. Default tuning_loop_count is set to same as existing loop count of MAX_TUNING_LOOP which is 40 iterations. Tested-by: Jon Hunter Signed-off-by: Sowjanya Komatineni Acked-by: Adrian Hunter Signed-off-by: Ulf Hansson --- drivers/mmc/host/sdhci.c | 5 +++-- drivers/mmc/host/sdhci.h | 1 + 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c index a8141ff9be03..bbc0e0bb7128 100644 --- a/drivers/mmc/host/sdhci.c +++ b/drivers/mmc/host/sdhci.c @@ -2369,9 +2369,9 @@ static int __sdhci_execute_tuning(struct sdhci_host *host, u32 opcode) /* * 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 < host->tuning_loop_count; i++) { u16 ctrl; sdhci_send_tuning(host, opcode); @@ -3494,6 +3494,7 @@ struct sdhci_host *sdhci_alloc_host(struct device *dev, host->cqe_err_ier = SDHCI_CQE_INT_ERR_MASK; host->tuning_delay = -1; + host->tuning_loop_count = MAX_TUNING_LOOP; host->sdma_boundary = SDHCI_DEFAULT_BOUNDARY_ARG; diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h index 01002cba1359..57bb3e3dca89 100644 --- a/drivers/mmc/host/sdhci.h +++ b/drivers/mmc/host/sdhci.h @@ -596,6 +596,7 @@ struct sdhci_host { #define SDHCI_TUNING_MODE_3 2 /* Delay (ms) between tuning commands */ int tuning_delay; + int tuning_loop_count; /* Host SDMA buffer boundary. */ u32 sdma_boundary; -- GitLab