5.4-stable review patch. If anyone has any objections, please let me know.
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From: Jorge Ramirez-Ortiz jorge@foundries.io
commit 67380251e8bbd3302c64fea07f95c31971b91c22 upstream.
Requesting a retune before switching to the RPMB partition has been observed to cause CRC errors on the RPMB reads (-EILSEQ).
Since RPMB reads can not be retried, the clients would be directly affected by the errors.
This commit disables the retune request prior to switching to the RPMB partition: mmc_retune_pause() no longer triggers a retune before the pause period begins.
This was verified with the sdhci-of-arasan driver (ZynqMP) configured for HS200 using two separate eMMC cards (DG4064 and 064GB2). In both cases, the error was easy to reproduce triggering every few tenths of reads.
With this commit, systems that were utilizing OP-TEE to access RPMB variables will experience an enhanced performance. Specifically, when OP-TEE is configured to employ RPMB as a secure storage solution, it not only writes the data but also the secure filesystem within the partition. As a result, retrieving any variable involves multiple RPMB reads, typically around five.
For context, on ZynqMP, each retune request consumed approximately 8ms. Consequently, reading any RPMB variable used to take at the very minimum 40ms.
After droping the need to retune before switching to the RPMB partition, this is no longer the case.
Signed-off-by: Jorge Ramirez-Ortiz jorge@foundries.io Acked-by: Avri Altman avri.altman@wdc.com Acked-by: Adrian Hunter adrian.hunter@intel.com Link: https://lore.kernel.org/r/20240103112911.2954632-1-jorge@foundries.io Signed-off-by: Ulf Hansson ulf.hansson@linaro.org Signed-off-by: Florian Fainelli florian.fainelli@broadcom.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/mmc/core/host.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/drivers/mmc/core/host.c +++ b/drivers/mmc/core/host.c @@ -111,13 +111,12 @@ void mmc_retune_enable(struct mmc_host *
/* * Pause re-tuning for a small set of operations. The pause begins after the - * next command and after first doing re-tuning. + * next command. */ void mmc_retune_pause(struct mmc_host *host) { if (!host->retune_paused) { host->retune_paused = 1; - mmc_retune_needed(host); mmc_retune_hold(host); } }