From 2b76e0cc7803e5ab561c875edaba7f6bbd87fbb0 Mon Sep 17 00:00:00 2001 From: Matthew Schwartz Date: Mon, 2 Mar 2026 13:07:17 -0800 Subject: mmc: sdhci-pci-gli: fix GL9750 DMA write corruption The GL9750 SD host controller has intermittent data corruption during DMA write operations. The GM_BURST register's R_OSRC_Lmt field (bits 17:16), which limits outstanding DMA read requests from system memory, is not being cleared during initialization. The Windows driver sets R_OSRC_Lmt to zero, limiting requests to the smallest unit. Clear R_OSRC_Lmt to match the Windows driver behavior. This eliminates write corruption verified with f3write/f3read tests while maintaining DMA performance. Cc: stable@vger.kernel.org Fixes: e51df6ce668a ("mmc: host: sdhci-pci: Add Genesys Logic GL975x support") Closes: https://lore.kernel.org/linux-mmc/33d12807-5c72-41ce-8679-57aa11831fad@linux.dev/ Acked-by: Adrian Hunter Signed-off-by: Matthew Schwartz Reviewed-by: Ben Chuang Signed-off-by: Ulf Hansson --- drivers/mmc/host/sdhci-pci-gli.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/mmc/host/sdhci-pci-gli.c b/drivers/mmc/host/sdhci-pci-gli.c index b0f91cc9e40e..6e4084407662 100644 --- a/drivers/mmc/host/sdhci-pci-gli.c +++ b/drivers/mmc/host/sdhci-pci-gli.c @@ -68,6 +68,9 @@ #define GLI_9750_MISC_TX1_DLY_VALUE 0x5 #define SDHCI_GLI_9750_MISC_SSC_OFF BIT(26) +#define SDHCI_GLI_9750_GM_BURST_SIZE 0x510 +#define SDHCI_GLI_9750_GM_BURST_SIZE_R_OSRC_LMT GENMASK(17, 16) + #define SDHCI_GLI_9750_TUNING_CONTROL 0x540 #define SDHCI_GLI_9750_TUNING_CONTROL_EN BIT(4) #define GLI_9750_TUNING_CONTROL_EN_ON 0x1 @@ -345,10 +348,16 @@ static void gli_set_9750(struct sdhci_host *host) u32 misc_value; u32 parameter_value; u32 control_value; + u32 burst_value; u16 ctrl2; gl9750_wt_on(host); + /* clear R_OSRC_Lmt to avoid DMA write corruption */ + burst_value = sdhci_readl(host, SDHCI_GLI_9750_GM_BURST_SIZE); + burst_value &= ~SDHCI_GLI_9750_GM_BURST_SIZE_R_OSRC_LMT; + sdhci_writel(host, burst_value, SDHCI_GLI_9750_GM_BURST_SIZE); + driving_value = sdhci_readl(host, SDHCI_GLI_9750_DRIVING); pll_value = sdhci_readl(host, SDHCI_GLI_9750_PLL); sw_ctrl_value = sdhci_readl(host, SDHCI_GLI_9750_SW_CTRL); -- cgit v1.2.3