ahci: Marvell 88SE9215 controllers prefer DMA for ATAPI

We use CD/DVD drives under Marvell 88SE9215 SATA controller on many
Loongson-based machines. We found its PIO doesn't work well, and on the
opposite its DMA seems work very well.

We don't know the detail of the 88SE9215 SATA controller, but we have
tested different CD/DVD drives and they all have problems under 88SE9215
(but they all work well under an Intel SATA controller). So, we consider
this problem is bound to 88SE9215 SATA controller rather than bound to
CD/DVD drives.

As a solution, we define a new dedicated AHCI board id which is named
board_ahci_yes_fbs_atapi_dma for 88SE9215, and for this id we set the
AHCI_HFLAG_ATAPI_DMA_QUIRK and ATA_QUIRK_ATAPI_MOD16_DMA flags on the
SATA controller in order to prefer ATAPI DMA.

Reported-by: Yuli Wang <wangyuli@uniontech.com>
Tested-by: Jie Fan <fanjie@uniontech.com>
Tested-by: Erpeng Xu <xuerpeng@uniontech.com>
Tested-by: Yuli Wang <wangyuli@uniontech.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Link: https://lore.kernel.org/r/20250318104314.2160526-1-chenhuacai@loongson.cn
Signed-off-by: Niklas Cassel <cassel@kernel.org>

diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index 52ae8f9a7dd619164134a542f72015d49b5db5a8..f3a6bfe098cd403bc7e8affe3666ea50f0bcf711 100644 (file)
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -63,6 +63,7 @@ enum board_ids {
        board_ahci_pcs_quirk_no_devslp,
        board_ahci_pcs_quirk_no_sntf,
        board_ahci_yes_fbs,
+       board_ahci_yes_fbs_atapi_dma,
 
        /* board IDs for specific chipsets in alphabetical order */
        board_ahci_al,
@@ -188,6 +189,14 @@ static const struct ata_port_info ahci_port_info[] = {
                .udma_mask      = ATA_UDMA6,
                .port_ops       = &ahci_ops,
        },
+       [board_ahci_yes_fbs_atapi_dma] = {
+               AHCI_HFLAGS     (AHCI_HFLAG_YES_FBS |
+                                AHCI_HFLAG_ATAPI_DMA_QUIRK),
+               .flags          = AHCI_FLAG_COMMON,
+               .pio_mask       = ATA_PIO4,
+               .udma_mask      = ATA_UDMA6,
+               .port_ops       = &ahci_ops,
+       },
        /* by chipsets */
        [board_ahci_al] = {
                AHCI_HFLAGS     (AHCI_HFLAG_NO_PMP | AHCI_HFLAG_NO_MSI),
@@ -590,7 +599,7 @@ static const struct pci_device_id ahci_pci_tbl[] = {
        { PCI_DEVICE(PCI_VENDOR_ID_MARVELL_EXT, 0x91a3),
          .driver_data = board_ahci_yes_fbs },
        { PCI_DEVICE(PCI_VENDOR_ID_MARVELL_EXT, 0x9215),
-         .driver_data = board_ahci_yes_fbs },
+         .driver_data = board_ahci_yes_fbs_atapi_dma },
        { PCI_DEVICE(PCI_VENDOR_ID_MARVELL_EXT, 0x9230),
          .driver_data = board_ahci_yes_fbs },
        { PCI_DEVICE(PCI_VENDOR_ID_MARVELL_EXT, 0x9235),

diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 8e895ae45c86b3d8597b4c122f4da1106b00451c..ba8b811fbe30d38cec2f819b709c33d5320ab7f3 100644 (file)
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -246,6 +246,7 @@ enum {
        AHCI_HFLAG_NO_SXS               = BIT(26), /* SXS not supported */
        AHCI_HFLAG_43BIT_ONLY           = BIT(27), /* 43bit DMA addr limit */
        AHCI_HFLAG_INTEL_PCS_QUIRK      = BIT(28), /* apply Intel PCS quirk */
+       AHCI_HFLAG_ATAPI_DMA_QUIRK      = BIT(29), /* force ATAPI to use DMA */
 
        /* ap->flags bits */
 

diff --git a/drivers/ata/libahci.c b/drivers/ata/libahci.c
index fdfa7b2662180b6593c7133f516edd0c5a8a048f..a28ffe1e5969182cf4b2025cb71325b26f6dedb1 100644 (file)
--- a/drivers/ata/libahci.c
+++ b/drivers/ata/libahci.c
@@ -1321,6 +1321,10 @@ static void ahci_dev_config(struct ata_device *dev)
 {
        struct ahci_host_priv *hpriv = dev->link->ap->host->private_data;
 
+       if ((dev->class == ATA_DEV_ATAPI) &&
+           (hpriv->flags & AHCI_HFLAG_ATAPI_DMA_QUIRK))
+               dev->quirks |= ATA_QUIRK_ATAPI_MOD16_DMA;
+
        if (hpriv->flags & AHCI_HFLAG_SECT255) {
                dev->max_sectors = 255;
                ata_dev_info(dev,