diff options
| author | Niklas Cassel <cassel@kernel.org> | 2025-02-21 02:54:23 +0100 |
|---|---|---|
| committer | Niklas Cassel <cassel@kernel.org> | 2025-02-21 18:28:22 +0100 |
| commit | 91ec84f8eaddbc93d7c62e363d68aeb7b89879c7 (patch) | |
| tree | 8493dc3b49aaef616c18b1ccb6e443e5e370aa71 | |
| parent | 08a04e20593b8efbc6dae99be6e965104826bfe1 (diff) | |
ata: libata-eh: Do not use ATAPI DMA for a device limited to PIO mode
atapi_eh_request_sense() currently uses ATAPI DMA if the SATA controller
has ATA_FLAG_PIO_DMA (PIO cmds via DMA) set.
However, ATA_FLAG_PIO_DMA is a flag that can be set by a low-level driver
on a port at initialization time, before any devices are scanned.
If a controller detects a connected device that only supports PIO, we set
the flag ATA_DFLAG_PIO.
Modify atapi_eh_request_sense() to not use ATAPI DMA if the connected
device only supports PIO.
Reported-by: Philip Pemberton <lists@philpem.me.uk>
Closes: https://lore.kernel.org/linux-ide/c6722ee8-5e21-4169-af59-cbbae9edc02f@philpem.me.uk/
Tested-by: Philip Pemberton <lists@philpem.me.uk>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Link: https://lore.kernel.org/r/20250221015422.20687-2-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>
| -rw-r--r-- | drivers/ata/libata-eh.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/ata/libata-eh.c b/drivers/ata/libata-eh.c index 3b303d4ae37a..16cd676eae1f 100644 --- a/drivers/ata/libata-eh.c +++ b/drivers/ata/libata-eh.c @@ -1542,8 +1542,15 @@ unsigned int atapi_eh_request_sense(struct ata_device *dev, tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE; tf.command = ATA_CMD_PACKET; - /* is it pointless to prefer PIO for "safety reasons"? */ - if (ap->flags & ATA_FLAG_PIO_DMA) { + /* + * Do not use DMA if the connected device only supports PIO, even if the + * port prefers PIO commands via DMA. + * + * Ideally, we should call atapi_check_dma() to check if it is safe for + * the LLD to use DMA for REQUEST_SENSE, but we don't have a qc. + * Since we can't check the command, perhaps we should only use pio? + */ + if ((ap->flags & ATA_FLAG_PIO_DMA) && !(dev->flags & ATA_DFLAG_PIO)) { tf.protocol = ATAPI_PROT_DMA; tf.feature |= ATAPI_PKT_DMA; } else { |