kernel.git/drivers/tty/serial/pch_uart.c, branch linux-5.10.y

pch_uart: Fix dma_sync_sg_for_device() nents value

2025-08-28T14:22:27Z

commit 6c0e9f05c9d7875995b0e92ace71be947f280bbd upstream. The dma_sync_sg_for_device() functions should be called with the same nents as the dma_map_sg(), not the value the map function returned according to the documentation in Documentation/core-api/dma-api.rst:450: With the sync_sg API, all the parameters must be the same as those passed into the sg mapping API. Fixes: da3564ee027e ("pch_uart: add multi-scatter processing") Cc: stable Signed-off-by: Thomas Fourier Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/20250701113452.18590-2-fourier.thomas@gmail.com Signed-off-by: Greg Kroah-Hartman

serial: pch_uart: Pass correct sg to dma_unmap_sg()

2023-01-24T06:20:00Z

commit e8914b52e5b024e4af3d810a935fe0805eee8a36 upstream. A local variable sg is used to store scatterlist pointer in pch_dma_tx_complete(). The for loop doing Tx byte accounting before dma_unmap_sg() alters sg in its increment statement. Therefore, the pointer passed into dma_unmap_sg() won't match to the one given to dma_map_sg(). To fix the problem, use priv->sg_tx_p directly in dma_unmap_sg() instead of the local variable. Fixes: da3564ee027e ("pch_uart: add multi-scatter processing") Cc: stable@vger.kernel.org Signed-off-by: Ilpo Järvinen Link: https://lore.kernel.org/r/20230103093435.4396-1-ilpo.jarvinen@linux.intel.com Signed-off-by: Greg Kroah-Hartman

serial: pch: Fix PCI device refcount leak in pch_request_dma()

2023-01-14T09:15:56Z

[ Upstream commit 8be3a7bf773700534a6e8f87f6ed2ed111254be5 ] As comment of pci_get_slot() says, it returns a pci_device with its refcount increased. The caller must decrement the reference count by calling pci_dev_put(). Since 'dma_dev' is only used to filter the channel in filter(), we can call pci_dev_put() before exiting from pch_request_dma(). Add the missing pci_dev_put() for the normal and error path. Fixes: 3c6a483275f4 ("Serial: EG20T: add PCH_UART driver") Signed-off-by: Xiongfeng Wang Link: https://lore.kernel.org/r/20221122114559.27692-1-wangxiongfeng2@huawei.com Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin

serial: pch: don't overwrite xmit->buf[0] by x_char

2022-06-09T08:21:28Z

commit d9f3af4fbb1d955bbaf872d9e76502f6e3e803cb upstream. When x_char is to be sent, the TX path overwrites whatever is in the circular buffer at offset 0 with x_char and sends it using pch_uart_hal_write(). I don't understand how this was supposed to work if xmit->buf[0] already contained some character. It must have been lost. Remove this whole pop_tx_x() concept and do the work directly in the callers. (Without printing anything using dev_dbg().) Cc: Fixes: 3c6a483275f4 (Serial: EG20T: add PCH_UART driver) Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20220503080808.28332-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

pch_uart: drop double zeroing

2020-09-27T12:17:43Z

sg_init_table zeroes its first argument, so the allocation of that argument doesn't have to. the semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // @@ expression x,n,flags; @@ x = - kcalloc + kmalloc_array (n,sizeof(struct scatterlist),flags) ... sg_init_table(x,n) // Signed-off-by: Julia Lawall Link: https://lore.kernel.org/r/1600601186-7420-2-git-send-email-Julia.Lawall@inria.fr Signed-off-by: Greg Kroah-Hartman

serial: pch_uart: use generic power management

2020-07-21T18:04:54Z

Drivers using legacy PM have to manage PCI states and device's PM states themselves. They also need to take care of configuration registers. With improved and powerful support of generic PM, PCI Core takes care of above mentioned, device-independent, jobs. This driver makes use of PCI helper functions like pci_save/restore_state(), pci_enable_device() and pci_set_power_state() to do required operations. In generic mode, they are no longer needed. Change function parameter in both .suspend() and .resume() to "struct device*" type. Use dev_get_drvdata() to get drv data. Compile-tested only. Signed-off-by: Vaibhav Gupta Link: https://lore.kernel.org/r/20200720120414.399961-1-vaibhavgupta40@gmail.com Signed-off-by: Greg Kroah-Hartman

tty: serial: pch_uart: Use scnprintf() for avoiding potential buffer overflow

2020-03-18T11:59:29Z

Since snprintf() returns the would-be-output size instead of the actual output size, the succeeding calls may go beyond the given buffer limit. Fix it by replacing with scnprintf(). Signed-off-by: Takashi Iwai Link: https://lore.kernel.org/r/20200311092930.24433-1-tiwai@suse.de Signed-off-by: Greg Kroah-Hartman

tty/serial: pmac_zilog: Don't check port->sysrq

2019-12-18T14:04:56Z

uart_handle_sysrq_char() already handles it. Signed-off-by: Dmitry Safonov Link: https://lore.kernel.org/r/20191213000657.931618-31-dima@arista.com Signed-off-by: Greg Kroah-Hartman

tty/serial: Migrate pch_uart to use has_sysrq

2019-12-18T14:04:55Z

The SUPPORT_SYSRQ ifdeffery is not nice as: - May create misunderstanding about sizeof(struct uart_port) between different objects - Prevents moving functions from serial_core.h - Reduces readability (well, it's ifdeffery - it's hard to follow) In order to remove SUPPORT_SYSRQ, has_sysrq variable has been added. Initialise it in driver's probe and remove ifdeffery. Signed-off-by: Dmitry Safonov Link: https://lore.kernel.org/r/20191213000657.931618-30-dima@arista.com Signed-off-by: Greg Kroah-Hartman

tty: serial: pch_uart: correct usage of dma_unmap_sg

2019-11-13T13:54:15Z

Per Documentation/DMA-API-HOWTO.txt, To unmap a scatterlist, just call: dma_unmap_sg(dev, sglist, nents, direction); .. note:: The 'nents' argument to the dma_unmap_sg call must be the _same_ one you passed into the dma_map_sg call, it should _NOT_ be the 'count' value _returned_ from the dma_map_sg call. However in the driver, priv->nent is directly assigned with value returned from dma_map_sg, and dma_unmap_sg use priv->nent for unmap, this breaks the API usage. So introduce a new entry orig_nent to remember 'nents'. Fixes: da3564ee027e ("pch_uart: add multi-scatter processing") Signed-off-by: Peng Fan Link: https://lore.kernel.org/r/1573623259-6339-1-git-send-email-peng.fan@nxp.com Signed-off-by: Greg Kroah-Hartman